Workflow fix (limosa-io#123)

Author: arietimmerman

.github/workflows/ci.yml

@@ -2,6 +2,10 @@ name: CI
 
 on: ['push', 'pull_request']
 
+permissions:
+  contents: read
+  packages: write
+
 jobs:
   tests:
     runs-on: ubuntu-latest
@@ -47,12 +51,13 @@ jobs:
       run: vendor/bin/phpunit
 
   docker:
+    # Only push Docker image for direct pushes to master branch
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
     runs-on: ubuntu-latest
     needs: tests
-    if: github.event_name == 'push' || github.event_name == 'pull_request'
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Log in to the Container registry
         uses: docker/login-action@v3
         with: