Build docker in PRs.

Author: simi

.github/workflows/ci.yml

@@ -143,8 +143,7 @@ jobs:
   docker-build:
     name: Build and Push Docker Test Image
     runs-on: ubuntu-latest
-    # Only run on pushes to main when Docker files change
-    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    if: github.event_name == 'pull_request' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
     permissions:
       contents: read
       packages: write
@@ -161,18 +160,20 @@ jobs:
             - 'docker-compose.yml'
 
     - name: Log in to GitHub Container Registry
-      if: steps.changes.outputs.docker == 'true'
+      if: steps.changes.outputs.docker == 'true' && github.event_name == 'push' && github.ref == 'refs/heads/main'
       uses: docker/login-action@v3
       with:
         registry: ghcr.io
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
 
-    - name: Build and push Docker image
+    - name: Build Docker image
       if: steps.changes.outputs.docker == 'true'
-      run: |
-        docker compose build
-        docker compose push
+      run: docker compose build
+
+    - name: Push Docker image
+      if: steps.changes.outputs.docker == 'true' && github.event_name == 'push' && github.ref == 'refs/heads/main'
+      run: docker compose push
 
   test-shellspec-linux:
     name: ShellSpec Tests (Linux)