Bump docker/build-push-action from 4.1.1 to 4.2.1

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 4.1.1 to 4.2.1.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v4.1.1...v4.2.1)

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

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

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -30,13 +30,13 @@ jobs:
         id: getversion
       - name: Push to GitHub Packages - Nightly
         if: ${{ github.ref == 'refs/heads/vnext' }}
-        uses: docker/build-push-action@v4.1.1
+        uses: docker/build-push-action@v4.2.1
         with:
           push: true
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:nightly
       - name: Push to GitHub Packages - Release
         if: ${{ github.ref == 'refs/heads/master' }}
-        uses: docker/build-push-action@v4.1.1
+        uses: docker/build-push-action@v4.2.1
         with:
           push: true
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest,${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.getversion.outputs.version }}