Bump docker/build-push-action from 6.10.0 to 6.13.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.10.0 to 6.13.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@48aba3b...ca877d9)

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

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

.github/workflows/testbuild.yml

@@ -40,7 +40,7 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@6524bf65af31da8d45b59e8c27de4bd072b392f5 # v3
       - name: Build Docker image
-        uses: docker/build-push-action@48aba3b46d1b1fec4febb7c5d0c644b249a11355 # v6
+        uses: docker/build-push-action@ca877d9245402d1537745e0e356eab47c3520991 # v6
         with:
           context: .
           push: false