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

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 4c1b68d83ad20cc1a09620ca477d5bbbb5fa14d0 to fdf7f43ecf7c1a5c7afe936410233728a8c2d9c2.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@4c1b68d...fdf7f43)

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

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

.github/workflows/build-container.yml

@@ -34,7 +34,7 @@ jobs:
         with:
           images: ${{ env.REGISTRY }}/freifunk-gluon/${{ env.IMAGE_NAME }}
       - name: Build and push Docker image
-        uses: docker/build-push-action@4c1b68d83ad20cc1a09620ca477d5bbbb5fa14d0
+        uses: docker/build-push-action@fdf7f43ecf7c1a5c7afe936410233728a8c2d9c2
         with:
           context: ./contrib/docker
           push: ${{ github.repository_owner == 'freifunk-gluon' && github.event_name == 'push' }}