gh-104812: Skip Pending Calls Tests if No Threading (gh-105761)

This fixes the WASM buildbots.

Author: ericsnowcurrently

Lib/test/test_capi/test_misc.py

@@ -1406,6 +1406,7 @@ def wait_for_result(self):
             while self.result is None:
                 time.sleep(0.01)
 
+    @threading_helper.requires_working_threading()
     def test_subthreads_can_handle_pending_calls(self):
         payload = 'Spam spam spam spam. Lovely spam! Wonderful spam!'
 
@@ -1421,6 +1422,7 @@ def do_the_work():
 
         self.assertEqual(task.result, payload)
 
+    @threading_helper.requires_working_threading()
     def test_many_subthreads_can_handle_pending_calls(self):
         main_tid = threading.get_ident()
         self.assertEqual(threading.main_thread().ident, main_tid)