Replace some include Kernel usages with requires_ancestor

[Bo98]

This didn't exist way back but does now.

For Utils::Shebang::* I have made it more stricter than necessary (requires_ancestor { Formula } rather than Kernel) purely because they are documented as a "Mixin module for Formula", though they don't actually need or use anything from Formula. I can make it Kernel if preferred.

[dduugg]

Just flagging that, AFAIK, all current usage of requires_ancestor is in rbi files, bc I didn't want the runtime to depend on an experimental sorbet feature.

That may have been overly cautious though, since we ship with sorbet-runtime bundled. (If so, we can probably ditch a few rbi files with a migration PR.)

[Bo98]

Hmm that's a fair point. Though AFAIK requires_ancestor is no-op at runtime anyway.

I don't really have a strong opinion either way.

[dduugg]

Hmm that's a fair point. Though AFAIK requires_ancestor is no-op at runtime anyway.

I don't really have a strong opinion either way.

Yep (pending TODO): https://github.com/sorbet/sorbet/blob/bb6e8f4/gems/sorbet-runtime/lib/types/helpers.rb#L63-L64

It's probably fine, just seems like a decision we should explicitly opt into.

[MikeMcQuaid]

Very nice, thanks @Bo98!