make stat.FILE_ATTRIBUTE_* available on all platforms (#14866)

stdlib/@tests/stubtest_allowlists/darwin.txt

@@ -53,9 +53,6 @@ multiprocessing.popen_spawn_win32  # exists on Darwin but fails to import
 readline.append_history_file  # Only available if compiled with GNU readline, not editline
 select.poll  # Actually a function; we have a class so it can be used as a type
 
-# Some of these exist on non-windows, but they are useless and this is not intended
-stat.FILE_ATTRIBUTE_[A-Z_]+
-
 tkinter.Tk.createfilehandler  # Methods that come from __getattr__() at runtime
 tkinter.Tk.deletefilehandler  # Methods that come from __getattr__() at runtime
 

stdlib/@tests/stubtest_allowlists/linux.txt

@@ -54,9 +54,6 @@ _?socket.SOL_IPX
 _?socket.SOL_NETROM
 _?socket.SOL_ROSE
 
-# Some of these exist on non-windows, but they are useless and this is not intended
-stat.FILE_ATTRIBUTE_[A-Z_]+
-
 # This is available on Linux, but it's documented as for kernel debugging and
 # not present on GitHub Actions runners.
 termios.TIOCTTYGSTRUCT