Bump docker/build-push-action from 2.6.1 to 4.2.1

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2.6.1 to 4.2.1.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v2.6.1...v4.2.1)

---
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/ci.yml

@@ -39,7 +39,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Push to GitHub Packages
-        uses: docker/build-push-action@v2.6.1
+        uses: docker/build-push-action@v4.2.1
         with:
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.docker_meta.outputs.tags }}