bpo-38323: Skip SubprocessMultiLoopWatcherTest as they can hang the test suite (GH-26542) (GH-26670)

(cherry picked from commit f171877)

Co-authored-by: Pablo Galindo <[email protected]>

Author: miss-islington

Lib/test/test_asyncio/test_subprocess.py

@@ -676,6 +676,8 @@ class SubprocessThreadedWatcherTests(SubprocessWatcherMixin,
 
         Watcher = unix_events.ThreadedChildWatcher
 
+    @unittest.skip("bpo-38323: MultiLoopChildWatcher has a race condition \
+                    and these tests can hang the test suite")
     class SubprocessMultiLoopWatcherTests(SubprocessWatcherMixin,
                                           test_utils.TestCase):