tools: ditch iwyu

CONTRIBUTING.md

@@ -62,9 +62,7 @@ even refuse to compile.
 
 This project uses [pre-commit](https://pre-commit.com/) to make sure the code
 is formatted the right way. This tool has additional external dependencies:
-`clang-format` for automatic code formatting and `include-what-you-use` to
-remove unused `#include`s.
-To install pre-commit:
+`clang-format` for automatic code formatting. To install pre-commit:
 
 ```
 python3 -m pip install --user pre-commit
@@ -74,7 +72,7 @@ pre-commit install
 To install required external dependencies on Ubuntu:
 
 ```
-apt-get install -y iwyu clang-format-18
+apt-get install -y clang-format-18
 ```
 
 After this, each time you make a commit a hook should trigger to automatically

src/game/game_string.c

@@ -4,9 +4,7 @@
 
 void GameString_Init(void)
 {
-    // IWYU pragma: begin_keep
 #include "game_string.def"
-    // IWYU pragma: end_keep
 }
 
 void GameString_Shutdown(void)