Bump pytest version

[pacrob]

Running pytest using python3.10, I see:

DeprecationWarning: You're using an outdated version of pytest. Newer releases of pytest-asyncio will not be compatible with this pytest version. Please update pytest to version 7 or later.

pytest --version yields pytest 6.2.5. It looks like pytest 7 still supports python 3.7.

[kclowes]

Closed via #2863