doc: require GHC >= 9.2.1 for ImpredicativeTypes

Author: EYH0602

README.md

@@ -18,13 +18,16 @@ uv sync # create a virtual environment, and install dependencies
 
 To run evaluation, you need GHC (the Glasgow Haskell Compiler) installed.
 We recommend using [ghcup](https://www.haskell.org/ghcup/) to install.
-You can use any version suggested by ghcup.
 
 ```sh
 curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
 ```
 
 Due to the GHC dependency, the evaluation module currently only supports Linux and macOS.
+Our evaluation requires Haskell language extensions [type operators](https://ghc.gitlab.haskell.org/ghc/doc/users_guide/exts/type_operators.html)
+and [impredicative polymorphism](https://ghc.gitlab.haskell.org/ghc/doc/users_guide/exts/impredicative_types.html),
+so we require GHC version >= 9.2.1.
+Our evaluation used GHC-9.6.7.
 
 ## Building TF-Bench From Scratch (Optional)