gh-124682: Disable test that is prone to intermittent failure on iOS. (…

…#124683)

Disable test that is prone to intermittent failure on iOS.

Lib/test/test_support.py

@@ -548,13 +548,14 @@ def test_optim_args_from_interpreter_flags(self):
             with self.subTest(opts=opts):
                 self.check_options(opts, 'optim_args_from_interpreter_flags')
 
+    @unittest.skipIf(support.is_apple_mobile, "Unstable on Apple Mobile")
     @unittest.skipIf(support.is_emscripten, "Unstable in Emscripten")
     @unittest.skipIf(support.is_wasi, "Unavailable on WASI")
     def test_fd_count(self):
-        # We cannot test the absolute value of fd_count(): on old Linux
-        # kernel or glibc versions, os.urandom() keeps a FD open on
-        # /dev/urandom device and Python has 4 FD opens instead of 3.
-        # Test is unstable on Emscripten. The platform starts and stops
+        # We cannot test the absolute value of fd_count(): on old Linux kernel
+        # or glibc versions, os.urandom() keeps a FD open on /dev/urandom
+        # device and Python has 4 FD opens instead of 3. Test is unstable on
+        # Emscripten and Apple Mobile platforms; these platforms start and stop
         # background threads that use pipes and epoll fds.
         start = os_helper.fd_count()
         fd = os.open(__file__, os.O_RDONLY)