maybe publish bottlerocket-variant

[webern]

Description

Consider publishing this as a separate tool and/or lib.

sources/bottlerocket-variant

I expect this will go away as we eliminate variant-specific builds of anything. If that matches your understanding, I'm cool with this being duplicated as well. Otherwise, potentially we could turn it into a CLI tool that build scripts can invoke.

Originally posted by @bcressey in https://github.com/bottlerocket-os/twoliter/issues/37#issuecomment-1692429512

Definition of Done

When bottlerocket-variant has been published to crates.io and Bottlerocket and Twoliter are both using it, OR, when we have decided not to do so.