* Replace all uses of StrPath, BytesPath, and AnyPath in Python 2 stubs.
* Add StrOrBytesPath as preferred alias for AnyPath.
* Replace all remaining AnyPath instances with StrOrBytesPath.
* Mark AnyPath as obsolete.
Part of #5470
Eliminated the use of "bare" TypeVars (i.e. a TypeVar that appears only once) within generic methods. While not considered an error in PEP 484, these are a common source of bugs in code, and some type checkers (including pytype and pyright) flag them as errors.
Co-authored-by: Eric Traut <erictr@microsoft.com>
