Bump docker/build-push-action from 2 to 2.4.0 (ChainSafe#633)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2 to 2.4.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v2...v2.4.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Diff for: .github/workflows/docker-build-and-push.yml

@@ -45,7 +45,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v2.4.0
         with:
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.prep.outputs.tags }}