👷 Add concurrency group to Docker build job to avoid redundant parallel builds (#1111)

Only the latest tag is pushed on main, so parallel runs waste resources.
Cancel in-progress builds when a newer push arrives.

Co-authored-by: OpenCode <noreply@opencode.ai>

Author: 0x46616c6b

.github/workflows/integration.yml

@@ -75,6 +75,9 @@ jobs:
     name: Build & Push Docker Image
     if: github.actor != 'dependabot[bot]'
     needs: test
+    concurrency:
+      group: docker-build-push
+      cancel-in-progress: true
     steps:
       - name: Checkout
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6