Bump docker/build-push-action from 3 to 4 (#6651)

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](https://github.com/docker/build-push-action/compare/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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

polkadot/.github/workflows/release-50_publish-docker-release.yml

@@ -27,7 +27,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Build and push
         id:   docker_build
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v4
         with:
           push: true
           file: scripts/ci/dockerfiles/polkadot_injected_release.Dockerfile

polkadot/.github/workflows/release-51_publish-docker-manual.yml

@@ -34,7 +34,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Build and push
         id:   docker_build
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v4
         with:
           push: true
           file: scripts/ci/dockerfiles/polkadot_injected_release.Dockerfile