Merge pull request #10 from dchesterton/dependabot/github_actions/docker/build-push-action-2.4.0

Bump docker/build-push-action from 2 to 2.4.0

.github/workflows/publish.yml

@@ -23,7 +23,7 @@ jobs:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
       - name: Build and push
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v2.4.0
         with:
           push: true
           platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/ppc64le,linux/s390x