regrtest can reports false SUCCESS and skip tests when a -j worker dies #101634

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0:04:46 load avg: 7.28 [ 48/434] test_isinstance passed -- running: test_largefile (2 min 54 sec)
0:05:03 load avg: 7.39 [ 49/434] test_utf8source passed -- running: test_largefile (3 min 11 sec), test_unittest (38.7 sec)
Warning -- regrtest worker thread failed: Traceback (most recent call last):
Warning --   File "/var/lib/buildbot/workers/3.x.gps-raspbian.nondebug/build/Lib/test/libregrtest/runtest_mp.py", line 342, in run
Warning --     mp_result = self._runtest(test_name)
Warning --                 ^^^^^^^^^^^^^^^^^^^^^^^^
Warning --   File "/var/lib/buildbot/workers/3.x.gps-raspbian.nondebug/build/Lib/test/libregrtest/runtest_mp.py", line 301, in _runtest
Warning --     stdout = stdout_fh.read().strip()
Warning --              ^^^^^^^^^^^^^^^^
Warning --   File "<frozen codecs>", line 322, in decode
Warning -- UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa9 in position 35: invalid start byte
Kill <TestWorkerProcess #1 running test=test_tempfile pid=7836 time=21.8 sec> process group
Kill <TestWorkerProcess #2 running test=test_largefile pid=7700 time=3 min 32 sec> process group

== Tests result: SUCCESS ==

385 tests omitted:
    test___all__ test__locale test__opcode test__osx_support
    test__xxinterpchannels test__xxsubinterpreters test_abc test_aifc
    test_argparse test_array test_asdl_parser test_ast test_asyncgen
    test_asyncio test_atexit test_audioop test_audit test_base64
...