As per [0], we want to investigate using a multi-module setup for our
`tools.go`.

This may be a bit of overhead to manage, so we can replace it if needed.

This takes us from 278M to 230M in terms of the dependency tree, which
is a slight improvement, but not the bulk of our overhead.

[0]: https://www.jvt.me/posts/2024/09/30/go-tools-module/