Fix os.chmod default value (#11775)

Author: nineteendo

stdlib/os/__init__.pyi

@@ -747,7 +747,7 @@ if sys.platform != "win32":
 
 def getcwd() -> str: ...
 def getcwdb() -> bytes: ...
-def chmod(path: FileDescriptorOrPath, mode: int, *, dir_fd: int | None = None, follow_symlinks: bool = True) -> None: ...
+def chmod(path: FileDescriptorOrPath, mode: int, *, dir_fd: int | None = None, follow_symlinks: bool = ...) -> None: ...
 
 if sys.platform != "win32" and sys.platform != "linux":
     def chflags(path: StrOrBytesPath, flags: int, follow_symlinks: bool = True) -> None: ...  # some flavors of Unix