Ryan Scott authored Jan 30, 2025 and Marge Bot committed Jun 18, 2025

!11314 introduced the `-Wdata-kinds-tc` warning as part of a fix for #22141.
This was a temporary stopgap measure to allow users who were accidentally
relying on code which needed the `DataKinds` extension in order to typecheck
without having to explicitly enable the extension.

Now that some amount of time has passed, this patch deprecates
`-Wdata-kinds-tc` and upgrades any `DataKinds`-related issues in the
typechecker (which were previously warnings) into errors.