Fix matrix exclude keys in build-dummy-app-webpack-test-bundles job

Adds the missing exclude section to the build-dummy-app-webpack-test-bundles
job to match the structure used in dummy-app-integration-tests job. This fixes
the GitHub Actions error where matrix exclude keys (ruby-version, node-version,
dependency-level) didn't match any keys within the matrix.

The exclude section prevents the minimum dependency matrix (Ruby 3.2, Node 20)
from running on regular PRs, ensuring it only runs on master, workflow_dispatch,
force_run, or when the full-ci label is present.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

.github/workflows/integration-tests.yml

@@ -73,6 +73,11 @@ jobs:
           - ruby-version: ${{ (github.ref == 'refs/heads/master' || inputs.force_run == true || needs.detect-changes.outputs.has_full_ci_label == 'true') && '3.2'}}
             node-version: ${{ (github.ref == 'refs/heads/master' || inputs.force_run == true || needs.detect-changes.outputs.has_full_ci_label == 'true') && '20'}}
             dependency-level: ${{ (github.ref == 'refs/heads/master' || inputs.force_run == true || needs.detect-changes.outputs.has_full_ci_label == 'true') && 'minimum'}}
+        exclude:
+          # Skip minimum dependency matrix on regular PRs (run only on master/workflow_dispatch/force_run/full-ci label)
+          - ruby-version: ${{ github.event_name == 'pull_request' && github.ref != 'refs/heads/master' && inputs.force_run != true && needs.detect-changes.outputs.has_full_ci_label != 'true' && '3.2' || '' }}
+            node-version: ${{ github.event_name == 'pull_request' && github.ref != 'refs/heads/master' && inputs.force_run != true && needs.detect-changes.outputs.has_full_ci_label != 'true' && '20' || '' }}
+            dependency-level: ${{ github.event_name == 'pull_request' && github.ref != 'refs/heads/master' && inputs.force_run != true && needs.detect-changes.outputs.has_full_ci_label != 'true' && 'minimum' || '' }}
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4