Add --build-arg and --build-secret

[fredericrous]

fix https://github.com/superfly/fly-pr-review-apps/issues/4

usage example

      - name: ✨ Deploy Preview
        uses: superfly/[email protected]
        with:
          build_args: |
            COMMIT_SHA=${{ github.sha }}
            OTHER_VARIABLE=true
          build_secrets: |
            SENTRY_AUTH_TOKEN=${{ secrets.SENTRY_AUTH_TOKEN }}

[pedroassumpcao]

This PR is great and fixes one of my needs as well.

[suddenlyGiovanni]

This PR is great and fixes one of my needs as well.

I have a use case where I rely on a different npm package registry. It requires a token to operate (read), so I need to provide access to it when the docker images are built. I'm doing that by passing it as a "build_arg" to fly deploy.

This is something that I can do with superfly/flyctl-actions/setup-flyctl@master, but can't with superfly/[email protected]

Please, consider it.

[KrisCoulson]

Would also love to see this get merged. We have a similar problem needing build args for our frontend services and SHA for issue tracking. Currently we have a fork of this repository to add this functionality. Would love to just be able to use the official action.

[harrygr]

+1 to get this merged.