Switch to PEP-604 syntax in python2 stubs (#5915)

Signed-off-by: oleg.hoefling <oleg.hoefling@gmail.com>

stdlib/@python2/sndhdr.pyi

@@ -1,6 +1,6 @@
-from typing import Optional, Text, Tuple, Union
+from typing import Text, Tuple, Union
 
 _SndHeaders = Tuple[str, int, int, int, Union[int, str]]
 
-def what(filename: Text) -> Optional[_SndHeaders]: ...
-def whathdr(filename: Text) -> Optional[_SndHeaders]: ...
+def what(filename: Text) -> _SndHeaders | None: ...
+def whathdr(filename: Text) -> _SndHeaders | None: ...