Test failure with 8.0.0 and pyqt5 on s390x

Updating the Fedora traitsui package to 8.0.0 and getting the following failure when the tests run on an s390x builder:
```
test_live_view_application_cancel (traitsui.tests.test_view_application.TestViewApplication.test_live_view_application_cancel) ... ERROR
Fatal Python error: Aborted
Current thread 0x000003ffa9ff7720 (most recent call first):
File "/usr/lib/python3.11/site-packages/pyface/ui/qt/util/event_loop_helper.py", line 164 in event_loop_until_condition
File "/usr/lib/python3.11/site-packages/pyface/ui/qt/util/event_loop_helper.py", line 76 in event_loop_with_timeout
File "/usr/lib/python3.11/site-packages/pyface/ui/qt/util/gui_test_assistant.py", line 332 in event_loop_with_timeout
File "/usr/lib64/python3.11/contextlib.py", line 144 in __exit__
File "/usr/lib/python3.11/site-packages/pyface/ui/qt/util/gui_test_assistant.py", line 70 in tearDown
File "/builddir/build/BUILDROOT/python-traitsui-8.0.0-1.fc39.noarch/usr/lib/python3.11/site-packages/traitsui/tests/test_view_application.py", line 62 in tearDown
File "/usr/lib64/python3.11/unittest/case.py", line 584 in _callTearDown
File "/usr/lib64/python3.11/unittest/case.py", line 626 in run
File "/usr/lib64/python3.11/unittest/case.py", line 678 in __call__
File "/usr/lib64/python3.11/unittest/suite.py", line 122 in run
File "/usr/lib64/python3.11/unittest/suite.py", line 84 in __call__
File "/usr/lib64/python3.11/unittest/suite.py", line 122 in run
File "/usr/lib64/python3.11/unittest/suite.py", line 84 in __call__
File "/usr/lib64/python3.11/unittest/suite.py", line 122 in run
File "/usr/lib64/python3.11/unittest/suite.py", line 84 in __call__
File "/usr/lib64/python3.11/unittest/suite.py", line 122 in run
File "/usr/lib64/python3.11/unittest/suite.py", line 84 in __call__
File "/usr/lib64/python3.11/unittest/runner.py", line 217 in run
File "/usr/lib64/python3.11/unittest/main.py", line 274 in runTests
File "/usr/lib64/python3.11/unittest/main.py", line 102 in __init__
File "/usr/lib64/python3.11/unittest/__main__.py", line 18 in
File "", line 88 in _run_code
File "", line 198 in _run_module_as_main
Extension modules: traits.ctraits, numpy.core._multiarray_umath, numpy.core._multiarray_tests, numpy.linalg._umath_linalg, numpy.fft._pocketfft_internal, numpy.random._common, numpy.random.bit_generator, numpy.random._bounded_integers, numpy.random._mt19937, numpy.random.mtrand, numpy.random._philox, numpy.random._pcg64, numpy.random._sfc64, numpy.random._generator, PyQt5.QtCore, PyQt5.QtGui, PyQt5.QtWidgets, PyQt5.QtPrintSupport, PyQt5.QtXml, PyQt5.QtTest, PyQt5.QtSql, PyQt5.QtOpenGL, PyQt5.QtDBus, PyQt5.QtNetwork, wx._core, numpy.linalg.lapack_lite, PIL._imaging (total: 27)
/usr/bin/xvfb-run: line 181: 6398 Aborted (core dumped) DISPLAY=:$SERVERNUM XAUTHORITY=$AUTHFILE "$@" 2>&1
```
Test run with:
```
+ export QT_API=pyqt5
+ QT_API=pyqt5
+ case $toolkit in
+ export ETS_TOOLKIT=qt
+ ETS_TOOLKIT=qt
+ export EXCLUDE_TESTS=wx
+ EXCLUDE_TESTS=wx
+ xvfb-run /usr/bin/python3 -s -X faulthandler -W default -m unittest discover -v traitsui
```