HaskellMouse authored Apr 27, 2022 and Marge Bot committed Jun 06, 2022

This commit fixes #20312
It deprecates "TypeInType" extension
according to the following proposal:
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0083-no-type-in-type.rst

It has been already implemented.

The migration strategy:
 1. Disable TypeInType
 2. Enable both DataKinds and PolyKinds extensions

Metric Decrease:
    T16875