Shim Removal

[Rspoon3]

Shims.swift is no longer needed since sleep(for:tolerance:) is now a native function.

[mbrandonw]

Hi @Rspoon3, while it is true sleep(for:) has been officially released, this library still supports older versions of Swift where it is not supported. So if we are going to remove the shims then we should also update Package.swift to be Swift 5.7. Would you mind adding that to this PR?

[Rspoon3]

@mbrandonw Yeah not a problem! Should the availability checks also be removed now?

[mbrandonw]

Yeah definitely, any mention of swift(>=5.7) can be removed.

[Rspoon3]

@mbrandonw Okay that should be everything now. Let me know if you'd like any other changes.

[mbrandonw]

Hi @Rspoon3, I think the changes to platforms in the Package.swift is going a little too far. That makes it so that packages that target iOS <16 cannot depend on this package, which means TCA could not even depend on it.

Can you revert that change and bring back all of the availability checks?

[Rspoon3]

All set.

[mbrandonw]

Thanks @Rspoon3!