fix: Remove missing type parameter

Author: KotlinIsland

coverage/types.py

@@ -13,7 +13,7 @@
 from types import FrameType, ModuleType
 from typing import (
     Any, Callable, Dict, Iterable, List, Mapping, Optional, Set, Tuple, Type, Union,
-    TYPE_CHECKING,
+    TYPE_CHECKING, AnyStr,
 )
 
 if TYPE_CHECKING:
@@ -29,7 +29,11 @@ class Protocol:             # pylint: disable=missing-class-docstring
 ## File paths
 
 # For arguments that are file paths:
-FilePath = Union[str, os.PathLike]
+if TYPE_CHECKING:
+    FilePath = Union[str, os.PathLike[str]]
+else:
+    # PathLike < python3.9 doesn't support subscription
+    FilePath = Union[str, os.PathLike]
 # For testing FilePath arguments
 FilePathClasses = [str, pathlib.Path]
 FilePathType = Union[Type[str], Type[pathlib.Path]]