Minor tweaks to regenerate-tags workflow

Author: MaddyGuthridge

.github/workflows/regenerate-tags.yml

@@ -40,7 +40,7 @@ jobs:
           body: |
             Regenerate tags for PyHTML by running `uv run -m generator`
 
-            This pull-request was auto-generated by GitHub Actions.
+            This pull-request was auto-generated.
           labels: |
             documentation
           assignees: MaddyGuthridge