reproducible failure of _compat_test.py

[pavoljuhas]

Description of the issue

How to reproduce the issue

Setup development environment for Python 3.9.16 and run

$ check/pytest -n 3 --durations=20 --randomly-seed=176322568 --ignore=cirq-core/cirq/contrib

Strangely when pytest is run only on cirq-core/cirq/_compat_test.py it is a pass.
There seems to be some interference with other tests.

Cirq version

1.4.0.dev at 3161d30
The failure shows for the Pytest MacOS (3.9) CI check in #6340.

[pavoljuhas]

This was fixed by #6374 and by the merge 011f3fb in #6340.