Support checks in forked repositories

Signed-off-by: Benoit Donneaux <benoit@leastauthority.com>

.forgejo/workflows/jekyll.yaml

@@ -80,7 +80,7 @@ jobs:
             ./_site/ "${WEB_USER}@${WEB_HOST}:${WEB_ROOT}${WEB_CONTEXT}"
       - name: Comment pull request
         id: comment_pull_request
-        if: ${{ always() && forge.event_name == 'pull_request' }}
+        if: ${{ always() && forge.event_name == 'pull_request' && ! forge.event.pull_request.head.repo.fork }}
         uses: https://github.com/exercism/pr-commenter-action@v1.5.1
         with:
           template-variables: |