Adjust custom-face-attributes for 'regular' weight

Following the changes to support "medium" weight fonts, the weight for
"normal" fonts is now reported as 'regular', which caused
customize-face to display faces as lisp-expressions, since it didn't
recognize that.  This has been corrected.

* lisp/cus-face.el (custom-face-attributes): Recognize 'regular' as a
weight.
1 job for master in 1 minute and 12 seconds (queued for 77 minutes and 40 seconds)
Status Job ID Name Coverage
  Normal
failed #33962
test-lisp-inotify

00:01:12

 
Name Stage Failure
failed
test-lisp-inotify Normal
error: pathspec 'lisp/better-pixel-scroll.el' did not match any file(s) known to git.
Running after script...
$ test -n "$(docker ps -aq -f name=${test_name})" && docker cp ${test_name}:checkout/test ${test_name}
$ test -n "$(docker ps -aq -f name=${test_name})" && docker rm ${test_name}
test-lisp-inotify-43a59578
Uploading artifacts...
WARNING: test-lisp-inotify-43a59578/lisp/*.log: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 123