Change ERC version to 5.6.1-git

* doc/misc/erc.texi: Change ERCVER to 5.6.1.
* lisp/erc/erc.el: (erc-version): Change working version to 5.6.1-git.
Do the same for the package Version header.  Don't bother updating
`customize-package-emacs-version-alist' until needed.

doc/misc/erc.texi

@@ -2,7 +2,7 @@
 @c %**start of header
 @setfilename ../../info/erc.info
 @settitle ERC Manual
-@set ERCVER 5.6
+@set ERCVER 5.6.1
 @set ERCDIST as distributed with Emacs @value{EMACSVER}
 @include docstyle.texi
 @syncodeindex fn cp

lisp/erc/erc.el

@@ -12,7 +12,7 @@
 ;;               David Edmondson (dme@dme.org)
 ;;               Michael Olson (mwolson@gnu.org)
 ;;               Kelvin White (kwhite@gnu.org)
-;; Version: 5.6
+;; Version: 5.6.1-git
 ;; Package-Requires: ((emacs "27.1") (compat "29.1.4.5"))
 ;; Keywords: IRC, chat, client, Internet
 ;; URL: https://www.gnu.org/software/emacs/erc.html
@@ -70,7 +70,7 @@
 (require 'auth-source)
 (eval-when-compile (require 'subr-x))
 
-(defconst erc-version "5.6"
+(defconst erc-version "5.6.1-git"
   "This version of ERC.")
 
 (defvar erc-official-location