Handle python3.14 ChildWatcher changes

Bug: https://bugs.gentoo.org/941955
Signed-off-by: Zac Medico <zmedico@gentoo.org>

lib/portage/tests/util/futures/asyncio/test_policy_wrapper_recursion.py

@@ -1,4 +1,4 @@
-# Copyright 2018 Gentoo Foundation
+# Copyright 2018-2024 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 import asyncio
@@ -17,7 +17,8 @@ def testPolicyWrapperRecursion(self):
             with self.assertRaises(NotImplementedError):
                 asyncio.get_event_loop()
 
-            with self.assertRaises(NotImplementedError):
-                asyncio.get_child_watcher()
+            if hasattr(asyncio, "get_child_watcher"):
+                with self.assertRaises(NotImplementedError):
+                    asyncio.get_child_watcher()
         finally:
             asyncio.set_event_loop_policy(initial_policy)

lib/portage/util/_eventloop/asyncio_event_loop.py

@@ -6,12 +6,16 @@
 
 import asyncio as _real_asyncio
 from asyncio.events import AbstractEventLoop as _AbstractEventLoop
-from asyncio.unix_events import ThreadedChildWatcher
 
 try:
-    from asyncio.unix_events import PidfdChildWatcher
+    from asyncio.unix_events import _ThreadedChildWatcher as ThreadedChildWatcher
 except ImportError:
-    PidfdChildWatcher = None
+    from asyncio.unix_events import ThreadedChildWatcher
+
+try:
+    from asyncio.unix_events import _PidfdChildWatcher as PidfdChildWatcher
+except ImportError:
+    from asyncio.unix_events import PidfdChildWatcher
 
 import portage
 
@@ -123,7 +127,8 @@ def _asyncio_child_watcher(self):
             else:
                 watcher = ThreadedChildWatcher()
 
-            watcher.attach_loop(self._loop)
+            if hasattr(watcher, "attach_loop"):
+                watcher.attach_loop(self._loop)
             self._child_watcher = _ChildWatcherThreadSafetyWrapper(self, watcher)
 
         return self._child_watcher

lib/portage/util/futures/unix_events.py

@@ -1,14 +1,10 @@
-# Copyright 2018-2021 Gentoo Authors
+# Copyright 2018-2024 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
-__all__ = (
-    "AbstractChildWatcher",
-    "DefaultEventLoopPolicy",
-)
+__all__ = ("DefaultEventLoopPolicy",)
 
 import asyncio as _real_asyncio
 from asyncio import events
-from asyncio.unix_events import AbstractChildWatcher
 
 import fcntl
 import os