bug#69084: 30; check-declare-directory chokes on lock files

[Jonas Bernoulli via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

`check-declare-directory' chokes on lock files for libraries:

  check-declare-scan: Opening input file: No such file or directory,
    /home/jonas/.config/emacs/lib/forge/lisp/.#forge-pullreq.el

This simple change would take care of that:

diff --git a/lisp/emacs-lisp/check-declare.el b/lisp/emacs-lisp/check-declare.el
@@ -328,7 +328,7 @@ check-declare-directory
   (setq root (directory-file-name (file-relative-name root)))
   (or (file-directory-p root)
       (error "Directory `%s' not found" root))
-  (let ((files (directory-files-recursively root "\\.el\\'")))
+  (let ((files (directory-files-recursively root "\\`[^.].*\\.el\\'")))
     (when files
       (apply #'check-declare-files files))))

I am not sure this is acceptable as it would also skip over other hidden
files.  IMO that would be okay; libraries arguably shouldn't be hidden
files.

     Cheers,
     Jonas