Announcing ERC 5.6.1

This point release contains a number of bug fixes as well as a few
tweaks to some recently introduced features. For a full rundown, see the
latest etc/ERC-NEWS [1] -- viewable from ERC with C-u M-x erc-news RET.

Users on Emacs 30 can upgrade with C-u M-x package-install RET. Users on
older versions, please see (info "(erc) Upgrading") [2].

A hearty thanks to the following folks for their thoughtful contributions:

 - Trevor Arjeski for a number of quality bug reports across ERC
 - Anush V for reporting an issue with the Imenu integration and which-func
 - DU Zaichuan for reporting a bad integration with kill-ring-deindent-mode
 - Alcor for pointing out a bad undo regression and other issues
 - Morgan Willcock for reporting a stray binding
 - Alex Bochannek for adding an untrack command
 - Mattias Engdeg=C3=A5rd and Bruno Boal for fixing bad Custom types
 - Archie Halliwell for highlighting a client-cert issue in the docs
 - Ulrich Mueller and Andrea Corallo for exposing shoddily written tests
 - Corwin for giving feedback on patches
 - Stefan Kangas for bug triage and various spelling and doc fixes
 - Anark Karabey for expressing concern about features added in 5.6
 - Joel Reicher for continued help debugging #erc's tracker relay bot
 - Paul Eggert for reporting failing tests on Solaris 10

And a huge apology for the massive delay in getting this out. More
consistency in the future might be a worthy goal.

J.P.

[1] https://git.savannah.gnu.org/cgit/emacs.git/tree/etc/ERC-NEWS
[2] https://elpa.gnu.org/devel/doc/erc.html#Upgrading