WIP 3.14t support

[crusaderky]

Warning-related test failures:
These are due to a difference between 3.14 and 3.14t, which causes warnings to be contextvars-based. This causes pytest.warns and pytest.mark.filterwarnings not to catch warnings emitted by a thread which was started before the filter was set - such as in workers started by the c fixture. So it should just be a matter of tweaking the tests.

FAILED distributed/diagnostics/tests/test_nanny_plugin.py::test_duck_typed_register_nanny_plugin_is_deprecated - Exception: DeprecationWarning('Registering duck-typed plugins has been deprecated. Please make sure your plugin inherits from `NannyPlugin`.')
FAILED distributed/diagnostics/tests/test_scheduler_plugin.py::test_register_plugin - Failed: DID NOT WARN. No warnings of type (<class 'UserWarning'>,) were emitted.
FAILED distributed/diagnostics/tests/test_worker_plugin.py::test_duck_typed_register_worker_plugin_is_deprecated - Exception: DeprecationWarning('Registering duck-typed plugins has been deprecated. Please make sure your plugin subclasses `WorkerPlugin`.')
FAILED distributed/tests/test_client.py::test_warn_manual - Failed: DID NOT WARN. No warnings of type (<class 'UserWarning'>,) were emitted.
FAILED distributed/tests/test_client.py::test_warn_remote - Failed: DID NOT WARN. No warnings of type (<class 'UserWarning'>,) were emitted.
FAILED distributed/tests/test_semaphore.py::test_close_async - Failed: DID NOT WARN. No warnings of type (<class 'RuntimeWarning'>,) were emitted.

Other test failures, which I have not investigated yet:

FAILED distributed/dashboard/tests/test_scheduler_bokeh.py::test_FinePerformanceMetrics - KeyError: 'evict(): dictionary is empty'
FAILED distributed/deploy/tests/test_old_ssh.py::test_cluster - AttributeError: 'SSHCluster' object has no attribute 'status'
FAILED distributed/deploy/tests/test_ssh.py::test_old_ssh_with_local_dir - AttributeError: 'SSHCluster' object has no attribute 'status'
FAILED distributed/protocol/tests/test_protocol.py::test_fallback_to_pickle - assert "can not serialize 'numpy.int64'" in 'Failed to serialize (Cannot serialize np.int64(1)); falling back to pickle. Be aware that this may de...
FAILED distributed/tests/test_spans.py::test_task_groups[False] - AssertionError: assert 272 == 240
FAILED distributed/tests/test_spans.py::test_task_groups[True] - AssertionError: assert 272 == 240
FAILED distributed/tests/test_spill.py::test_spillbuffer - AssertionError: assert {'b': 'bbbbbb...bbbbbbbbbbbb'} == {'a': 'aaaaaa...bbbbbbbbbbbb'}
FAILED distributed/tests/test_steal.py::test_new_worker_steals - TimeoutError: Test timeout (30) hit after 30.001825239000027s.
FAILED distributed/tests/test_steal.py::test_steal_twice - assert 33 < 30
FAILED distributed/tests/test_steal.py::test_cleanup_repeated_tasks - AssertionError: assert not [<test_steal.test_cleanup_repeated_tasks.<locals>.Foo object at 0x57d202a7400>, <test_steal.test_cleanup_repeated_tasks...
ERROR distributed/deploy/tests/test_old_ssh.py::test_cluster - Failed: 3 thread(s) were leaked from test
ERROR distributed/deploy/tests/test_old_ssh.py::test_old_ssh_nprocs_renamed_to_n_workers - ExceptionGroup: multiple thread exception warnings (2 sub-exceptions)
ERROR distributed/deploy/tests/test_ssh.py::test_defer_to_old - Failed: 2 thread(s) were leaked from test
ERROR distributed/deploy/tests/test_ssh.py::test_old_ssh_with_local_dir - Failed: 3 thread(s) were leaked from test

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

    33 files  +    2      33 suites  +2   11h 45m 15s ⏱️ + 17m 46s
 4 113 tests ±    0   3 993 ✅  -    10    104 💤 ±  0  16 ❌ +10 
63 688 runs  +4 052  61 092 ✅ +3 936  2 580 💤 +106  16 ❌ +10 

For more details on these failures, see this check.

Results for commit e4f757e. ± Comparison against base commit 4fb4814.

♻️ This comment has been updated with latest results.