os.get_terminal_size also exists on Windows

... at least according to https://docs.python.org/3/library/os.html#os.get_terminal_size.

Related to python/mypy#5370.

Author: JelleZijlstra

stdlib/3/os/__init__.pyi

@@ -362,8 +362,8 @@ if sys.platform != 'win32':
         def readv(fd: int, buffers: Sequence[bytearray]) -> int: ...
         def writev(fd: int, buffers: Sequence[bytes]) -> int: ...
 
-    terminal_size = NamedTuple('terminal_size', [('columns', int), ('lines', int)])
-    def get_terminal_size(fd: int = ...) -> terminal_size: ...
+terminal_size = NamedTuple('terminal_size', [('columns', int), ('lines', int)])
+def get_terminal_size(fd: int = ...) -> terminal_size: ...
 
 if sys.version_info >= (3, 4):
     def get_inheritable(fd: int) -> bool: ...