test_proc_reader_send_signit is unreliable on Ubuntu for Python 3.12 & 3.13

[tleonhardt]

The test_proc_reader_send_signit unit test in tests/test_utils.py has intermittent reliability issues on Ubuntu for Python 3.12 and 3.13.

We have seen intermittent failures with this test on Ubuntu when using Python 3.12 or 3.13. We have not seen failures for other OSes or versions of Python.

[tleonhardt]

#1364 should hopefully fix this, but we'll need to wait awhile after merging it to verify since it is an intermittent issue.

[tleonhardt]

It looks like this was fixed by #1364