chore(gha): avoid comment on PRs for check-changelog workflow (#8104)

Co-authored-by: César Arroba <19954079+cesararroba@users.noreply.github.com>

.github/workflows/pull-request-check-changelog.yml

@@ -55,7 +55,7 @@ jobs:
           body-includes: '<!-- changelog-check -->'
 
       - name: Comment on PR if changelog is missing
-        if: steps.check_folders.outputs.missing_changelogs != ''
+        if: github.event.pull_request.head.repo.full_name == github.repository && steps.check_folders.outputs.missing_changelogs != ''
         uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4.0.0
         with:
           issue-number: ${{ github.event.pull_request.number }}
@@ -69,7 +69,7 @@ jobs:
             Please add an entry to the corresponding `CHANGELOG.md` file to maintain a clear history of changes.
 
       - name: Comment on PR if all changelogs are present
-        if: steps.check_folders.outputs.missing_changelogs == ''
+        if: github.event.pull_request.head.repo.full_name == github.repository && steps.check_folders.outputs.missing_changelogs == ''
         uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4.0.0
         with:
           issue-number: ${{ github.event.pull_request.number }}