build(deps): bump docker/build-push-action

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from f2a1d5e99d037542a71f64918e516c093c6f3fc4 to 4c1b68d83ad20cc1a09620ca477d5bbbb5fa14d0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/f2a1d5e99d037542a71f64918e516c093c6f3fc4...4c1b68d83ad20cc1a09620ca477d5bbbb5fa14d0

)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
...

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

.github/workflows/build-container.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           images: ${{ env.REGISTRY }}/freifunk-gluon/${{ env.IMAGE_NAME }}
       - name: Build and push Docker image
-        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
+        uses: docker/build-push-action@4c1b68d83ad20cc1a09620ca477d5bbbb5fa14d0
         with:
           context: ./contrib/docker
           push: true