style: remove extra whitespace

Author: Ivernoerve

src/mkdocstrings_handlers/python/_internal/config.py

@@ -691,7 +691,7 @@ class PythonInputOptions:
     ] = True
 
     show_category_heading: Annotated[
-        Literal["mod",  "class", True, False],
+        Literal["mod", "class", True, False],
         _Field(
             group="headings",
             description="""When grouped by categories, show a heading for the categories.