Bump docker/build-push-action from 4 to 5

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 4 to 5.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v4...v5)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/build-image.yaml

@@ -56,7 +56,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Build and push unbound
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v5
         with:
           context: ./images
           platforms: linux/amd64,linux/arm64
@@ -66,7 +66,7 @@ jobs:
           file: ./images/Dockerfile
 
       - name: Build and push exporter
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v5
         with:
           context: ./images
           platforms: linux/amd64,linux/arm64