bug#81639: Please add alias from "ghostty" to "xterm" in faces.el

Ghostty is a terminal emulator that intends to be fully xterm 
compatible. Unfortunately, due to disagreements between the ncurses 
maintainers and the Ghostty maintainers, it has two TERM values: 
"xterm-ghostty" (preferred by ghostty maintainers) and "ghostty" 
(preferred by ncurses maintainers). Many people run with TERM set to 
"ghostty" because that's what ncurses packages, however that prevents 
Emacs from noticing that this terminal is xterm compatible.

Adding ("ghostty" . "xterm") to term-file-aliases enables Emacs to 
properly handle this terminal with both values.  It's a simple patch:

      ("vt420" . "vt200")
      ("alacritty" . "xterm")
      ("foot" . "xterm")
-    ("contour" . "xterm"))
+    ("contour" . "xterm")
+    ("ghostty" . "xterm"))
    "Alist of terminal type aliases.
  Entries are of the form (TYPE . ALIAS), where both elements are 
strings.
  This means to treat a terminal of type TYPE as if it were of type 
ALIAS."

   -- MJF