fix: silence 'missing lexical-binding cookie' warnings

As of recent commits of Emacs 31, elisp files missing a
"lexical-binding: t" cookie will emit this warning:

  Warning (files): Missing ‘lexical-binding’ cookie in "path/to/elisp/file".
  You can add one with ‘M-x elisp-enable-lexical-binding RET’.
  See ‘(elisp)Selecting Lisp Dialect’ and ‘(elisp)Converting to Lexical Binding’
  for more information.

You can look forward to many of these if you use any old and
unmaintained elisp packages, or if you have elisp shell scripts with
shebang lines (which make this warning unavoidable).

This commit silences these warnings because it's poorly implemented.
It's obnoxious to users and they aren't the ones that should be told
this. It ought to be emitted during byte-compilation or by linters (e.g.
`M-x checkdoc`) at the folks actually in a position to do something
about the warning (i.e. the developers).

Ref: https://lists.gnu.org/r/emacs-devel/2024-05/msg00283.html

bin/doomscript

@@ -38,7 +38,7 @@ esac
 # directory from `load-path', which would prevent Doom from manually loading the
 # site files later. These are important on some systems or deployment methods
 # (like Snap or NixOS).
-emacs="$EMACS -q --no-site-file --batch"
+emacs="$EMACS -q --no-site-file --batch --eval \"(setq warning-inhibit-types '((files missing-lexbind-cookie)))\""
 
 # Doom respects $EMACSDIR to tell it where Doom lives. If it fails, then this is
 # either isn't bash, or it's a posix shell being directly sourced with sh, which