fixup! [CI] Added preview bot

Author: mnocon

.github/workflows/preview_comment.yaml

@@ -10,6 +10,6 @@ jobs:
         permissions:
             # Needed to manage the comment
             pull-requests: write
-        uses: ibexa/documentation-developer/.github/workflows/preview_comment.yaml@main
+        uses: ibexa/documentation-developer/.github/workflows/preview_comment.yaml@master
         with:
             project: 'projects/userguide/'