ci(docker): upgrade build-push-action v5 to v7

v5 uses Node.js 20 which is deprecated by GitHub Actions.
v7 supports Node.js 24.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: theothersideofgod

.github/workflows/docker.yaml

@@ -91,7 +91,7 @@ jobs:
             type=sha,format=short,prefix=
 
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v7
         with:
           context: .
           file: generated/${{ matrix.dir }}/Dockerfile