bug#81514: 32.0.50; Eglot messages progress reporter shows errors

When Eglot is configured with `eglot-report-progress` set to `messages`, it
reports an error while trying to use the progress reporter in a nontrivial
project.

Reproduction using rust-analyzer:
1. Clone https://github.com/BurntSushi/ripgrep
2. Open ripgrep/crates/core/main.rs
3. M-: (setopt eglot-report-progress 'messages)
4. M-x toggle-debug-on-error
5. M-x eglot

Debugger entered--Lisp error: (wrong-type-argument sequencep 100)
   progress-reporter-echo-area((7 . [1785304002.532535 nil nil "[eglot] 
ripgrep rustAnalyzer/Building compile-time-deps: Building 
compile-time-deps..." 1 0.2 nil nil]) 7 100)
   progress-reporter-do-update((7 . [1785304002.532535 nil nil "[eglot] 
ripgrep rustAnalyzer/Building compile-time-deps: Building 
compile-time-deps..." 1 0.2 nil nil]) 100 nil)
   eglot--reporter-update((7 . [1785304002.532535 nil nil "[eglot] 
ripgrep rustAnalyzer/Building compile-time-deps: Building 
compile-time-deps..." 1 0.2 nil nil]) 100 nil)
   #f(compiled-function (arg1 arg2 arg3 arg4 &rest rest) #<bytecode 
0x1c7b74ccff3232d6>)(#<eglot-lsp-server 1008c31da7cc> 
"rustAnalyzer/Building compile-time-deps" 100 nil)
   #f(compiled-function (arg1 arg2 &rest rest) "Handle $/progress 
notification identified by TOKEN from SERVER." #<bytecode 
-0x35b89fe1a323862>)(#<eglot-lsp-server 1008c31da7cc> $/progress :token 
"rustAnalyzer/Building compile-time-deps" :value (:kind "end"))
   apply(#f(compiled-function (arg1 arg2 &rest rest) "Handle $/progress 
notification identified by TOKEN from SERVER." #<bytecode 
-0x35b89fe1a323862>) #<eglot-lsp-server 1008c31da7cc> $/progress (:token 
"rustAnalyzer/Building compile-time-deps" :value (:kind "end")))
   eglot-handle-notification(#<eglot-lsp-server 1008c31da7cc> $/progress 
:token "rustAnalyzer/Building compile-time-deps" :value (:kind "end"))
   apply(eglot-handle-notification #<eglot-lsp-server 1008c31da7cc> 
$/progress (:token "rustAnalyzer/Building compile-time-deps" :value 
(:kind "end")))
   #f(compiled-function (server method params) #<bytecode 
0x1f1068c682e838aa>)(#<eglot-lsp-server 1008c31da7cc> $/progress (:token 
"rustAnalyzer/Building compile-time-deps" :value (:kind "end")))
   jsonrpc-connection-receive(#<eglot-lsp-server 1008c31da7cc> (:jsonrpc 
"2.0" :method "$/progress" :params (:token "rustAnalyzer/Building 
compile-time-deps" :value (:kind "end"))))
   #f(compiled-function (conn msg) #<bytecode 
0x1bafe9b6d4ce09dc>)(#<eglot-lsp-server 1008c31da7cc> (:jsonrpc "2.0" 
:method "$/progress" :params (:token "rustAnalyzer/Building 
compile-time-deps" :value (:kind "end"))))
   apply(#f(compiled-function (conn msg) #<bytecode 0x1bafe9b6d4ce09dc>) 
(#<eglot-lsp-server 1008c31da7cc> (:jsonrpc "2.0" :method "$/progress" 
:params (:token "rustAnalyzer/Building compile-time-deps" :value (:kind 
"end")))))
   timer-event-handler([t 27241 37827 781121 nil #f(compiled-function 
(conn msg) #<bytecode 0x1bafe9b6d4ce09dc>) (#<eglot-lsp-server 
1008c31da7cc> (:jsonrpc "2.0" :method "$/progress" :params (:token 
"rustAnalyzer/Building compile-time-deps" :value (:kind "end")))) nil 
734000 nil])

This seems to be introduced by the following commit
https://github.com/emacs-mirror/emacs/commit/b6849229003f214570acedfa7e2755051c0e4305
and most likely affects Emacs 31 as well.


In GNU Emacs 32.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
  3.24.52, cairo version 1.18.4) of 2026-07-29 built on arch
Repository revision: 9a431e431ad92f94f4290c3f0bf043b0f97a7b56
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12401013
System Description: Arch Linux

Configured using:
  'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
  --localstatedir=/var --mandir=/usr/share/man --with-gameuser=:games
  --with-modules --without-m17n-flt --without-gconf
  --with-native-compilation=yes --with-xinput2 --with-x-toolkit=gtk3
  --without-xaw3d --with-sound=no --with-tree-sitter --without-gpm
  --without-compress-install 'CFLAGS=-march=native -O2 -pipe -fno-plt
  -fexceptions -Wp,-D_FORTIFY_SOURCE=3 -Wformat -Werror=format-security
  -fstack-clash-protection -fcf-protection -fno-omit-frame-pointer
  -mno-omit-leaf-frame-pointer' 'LDFLAGS=-Wl,-O1 -Wl,--sort-common
  -Wl,--as-needed -Wl,-z,relro -Wl,-z,now -Wl,-z,pack-relative-relocs
  -fuse-ld=mold''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG
LCMS2 LIBOTF LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER WEBP X11 XDBE XIM XINERAMA XINPUT2 XPM XRANDR GTK3 ZLIB

Important settings:
   value of $LC_MESSAGES: en_US.UTF-8
   value of $LANG: en_US.UTF-8
   value of $XMODIFIERS: im=fcit
   locale-coding-system: utf-8-unix

Major mode: Elisp/l

Minor modes in effect:
   eglot-semantic-tokens-mode: t
   eglot-inlay-hints-mode: t
   eglot--managed-mode: t
   flymake-mode: t
   tooltip-mode: t
   global-eldoc-mode: t
   eldoc-mode: t
   show-paren-mode: t
   electric-indent-mode: t
   mouse-wheel-mode: t
   tool-bar-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   minibuffer-nonselected-mode: t
   minibuffer-regexp-mode: t
   buffer-read-only: t
   line-number-mode: t
   indent-tabs-mode: t
   transient-mark-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug lisp-mnt message mailcap yank-media puny
rfc822 mml mml-sec epa derived epg rfc6068 epg-config gnus-util
mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader sendmail
mail-parse rfc2231 rfc2047 rfc2045 ietf-drums mm-util mail-prsvr
mail-utils help-fns radix-tree cl-print time-date byte-opt cl-extra
eglot tree-widget external-completion jsonrpc xref flymake thingatpt
project diff diff-mode track-changes easy-mmode ert ewoc debug backtrace
help-mode find-func filenotify warnings compile text-property-search
comint ansi-osc ansi-color ring url-util url-parse auth-source eieio
eieio-core cl-macs gv password-cache json subr-x mule-util map url-vars
imenu cus-edit pp cus-start cus-load icons wid-edit pcase vc-git files-x
vc-dispatcher cl-seq rust-ts-mode c-ts-common treesit comp-run bytecomp
byte-compile comp-common rx dired-aux cl-loaddefs cl-lib dired
dired-loaddefs rmc iso-transl tooltip cconv eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/x-win x-win term/common-win x-dnd touch-screen tool-bar dnd fontset
image regexp-opt fringe tabulated-list replace newcomment text-mode
lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch
easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting cairo gtk
x-toolkit xinput2 x multi-tty move-toolbar make-network-process
tty-child-frames native-compile emacs)

Memory information:
((conses 16 179879 13773) (symbols 48 14783 0) (strings 32 44223 2401)
  (string-bytes 1 1465434) (vectors 16 26030)
  (vector-slots 8 328856 9043) (floats 8 160 3) (intervals 56 2109 0)
  (buffers 1064 23))