ci: Make E2E tests required & check for PRs against master

Author: mydea

.github/workflows/build.yml

@@ -181,6 +181,21 @@ jobs:
     outputs:
       dependency_cache_key: ${{ steps.compute_lockfile_hash.outputs.hash }}
 
+  job_check_branches:
+    name: Check PR branches
+    needs: job_get_metadata
+    runs-on: ubuntu-20.04
+    if: github.event_name == 'pull_request'
+    permissions:
+      pull-requests: write
+    steps:
+      - name: PR is opened against master
+        uses: mshick/add-pr-comment@v2
+        if: github.ref == 'refs/heads/master' && github.head_ref != 'refs/heads/develop'
+        with:
+          message: |
+            ⚠️ This PR is opened against **master**. You probably want to open it against **develop**.
+
   job_build:
     name: Build
     needs: [job_get_metadata, job_install_deps]
@@ -709,6 +724,7 @@ jobs:
         job_browser_playwright_tests,
         job_browser_integration_tests,
         job_remix_integration_tests,
+        job_e2e_tests,
       ]
     # Always run this, even if a dependent job failed
     if: always()