Bump docker/build-push-action from 3 to 4

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 4.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v3...v4)

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

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

.github/workflows/build-docker.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v2
     - name: Build only
-      uses: docker/build-push-action@v3
+      uses: docker/build-push-action@v4
       with:
         context: .
         load: true
@@ -37,7 +37,7 @@ jobs:
         password: ${{ secrets.DOCKERHUB_TOKEN }}
     - name: Push to DockerHub
       if: env.DOCKER_PUSH_TAG != ''
-      uses: docker/build-push-action@v3
+      uses: docker/build-push-action@v4
       with:
         context: .
         push: true