CI: Avoid flaky hypothesis test with deadline=None
xref https://dev.azure.com/pandas-dev/pandas/_build/results?buildId=70928&view=logs&jobId=9dd5e044-6afa-5be6-cb56-860f1ee82b31&j=9dd5e044-6afa-5be6-cb56-860f1ee82b31&t=d3ae057b-d0af-59ce-6e4c-b69ef3739701

great, merge on green Failure due to stalled build