It should be just as as straightforward with Depot as well - we have a depot/build-push-action (https://github.com/depot/build-push-action) that accepts the same inputs as docker/build-push-action to make it easy (under the hood, both use BuildKit).

    steps:
      - uses: depot/setup-action@v1
      - uses: depot/build-push-action@v1
        with:
          platforms: linux/amd64,linux/arm64