Random test failure due to random unsafe port

[wch]

https://github.com/rstudio/py-shiny/actions/runs/5006847527/jobs/8972663184#step:6:1149

From the logs:

>       result = next(iter(done)).result()
E       playwright._impl._api_types.Error: net::ERR_UNSAFE_PORT at http://127.0.0.1:5060/
E       =========================== logs ===========================
E       navigating to "http://127.0.0.1:5060/", waiting until "load"
E       ============================================================

/opt/hostedtoolcache/Python/3.7.16/x64/lib/python3.7/site-packages/playwright/_impl/_connection.py:96: Error
============================= slowest 6 durations ==============================
5.25s call     e2e/examples/test_examples.py::test_examples[firefox-../../examples/static_plots/app.py]
5.06s call     e2e/examples/test_examples.py::test_examples[webkit-../../examples/static_plots/app.py]

(4 durations < 5s hidden.  Use -vv to show these durations.)
=========================== short test summary info ============================
FAILED e2e/examples/test_examples.py::test_examples[chromium-../../shiny/examples/input_action_button/app.py] - playwright._impl._api_types.Error: net::ERR_UNSAFE_PORT at http://127.0.0.1:5060/