Added support for PEP613 (TypeAlias) in typing.pyi (#4472)

Co-authored-by: Eric Traut <erictr@microsoft.com>

stdlib/3/typing.pyi

@@ -54,6 +54,7 @@ if sys.version_info >= (3, 10):
         __name__: str
         def __init__(self, name: str) -> None: ...
     Concatenate: _SpecialForm = ...
+    TypeAlias: _SpecialForm = ...
 
 # Return type that indicates a function does not return.
 # This type is equivalent to the None type, but the no-op Union is necessary to