ci: Bump docker/build-push-action from 5 to 7

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 7.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v5...v7)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/docker-validate.yml

@@ -128,7 +128,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
 
       - name: Build ${{ matrix.service }}
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v7
         with:
           context: ${{ matrix.context }}
           file: ${{ matrix.dockerfile }}