[gnome-shell] ci: Add commit rule to not end subject with punctuation

[Marge Bot <marge-bot src gnome org>]

commit 175175fac850019d3224bb4734886fa414aefe73
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Feb 26 14:46:22 2021 +0100

    ci: Add commit rule to not end subject with punctuation
    
    I recently forgot to fill in the subject after the prefix. Add a
    commit rule for catching this and other cases where subject lines
    end in punctuation (except ...)
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1722>

 .gitlab-ci/commit-rules.yml | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/.gitlab-ci/commit-rules.yml b/.gitlab-ci/commit-rules.yml
index 9770f45152..5828f8ad54 100644
--- a/.gitlab-ci/commit-rules.yml
+++ b/.gitlab-ci/commit-rules.yml
@@ -11,3 +11,6 @@ patterns:
     - regex: '^\S*\.(js|c|h):'
       message: Commit message subject prefix should not include .c, .h etc.
       where: subject
+    - regex: '([^.]\.|[:,;])\s*$'
+      message: Commit message subject should not end with punctuation
+      where: subject