do not specify sub-type with os.PathLike

Get a "TypeError: 'ABCMeta' object is not subscriptable" on Python 3.8

msl/loadlib/load_library.py

@@ -29,7 +29,7 @@
 # using TypeVar is equivalent for < 3.11
 Self = TypeVar('Self', bound='LoadLibrary')
 
-PathLike = TypeVar('PathLike', str, bytes, os.PathLike[str], os.PathLike[bytes])
+PathLike = TypeVar('PathLike', str, bytes, os.PathLike)
 """A :term:`path-like object`."""