Support checks in forked repositories

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

.forgejo/workflows/jekyll.yaml

@@ -56,6 +56,7 @@ jobs:
           jekyll build --verbose
       - name: Deploy Jekyll site
         id: deploy_site
+        if: ${{ ! forge.event.pull_request.head.repo.fork }}
         run: |
           if [ "${{ forge.ref }}" = 'refs/heads/main' ]; then
             WEB_ROOT="${WEB_DIR}/live"

.forgejo/workflows/jekyll_cleanup.yml

@@ -12,6 +12,7 @@ env:
   WEB_CONTEXT: "/${{ forge.event.pull_request.number }}/"
 jobs:
   jekyll_cleanup:
+    if: ${{ ! forge.event.pull_request.head.repo.fork }}
     runs-on: ubuntu-22.04
     permissions:
       pull-requests: read

README.md

@@ -21,3 +21,4 @@ docker-compose up
 
 We welcome contributions!  Easiest is to open tickets or pull requests directly.  If unsure, join the IRC or ask on the Tahoe-LAFS developer mailing list.
 
+**Caveat**: because they need access to the repository secrets (e.g. SSH private key), the deployment step will be skipped on forked repositories. Which means preview sites will only be published from local branches pushed by collaborators with permissions to write in this repository.