Remove unneeded annotation

Author: JukkaL

mypy/options.py

@@ -410,7 +410,7 @@ def __init__(self) -> None:
         self.mypyc_annotation_file: str | None = None
         # Skip writing C output files, but perform all other steps of a build (allows
         # preserving manual tweaks to generated C file)
-        self.mypyc_skip_c_generation: bool = False
+        self.mypyc_skip_c_generation = False
 
     def use_lowercase_names(self) -> bool:
         if self.python_version >= (3, 9):