Test ray on newer Python versions

[sentrivana]

It looks like we were only testing ray on Python 3.10 and 3.11. When migrating to toxgen, I didn't change this as it seemed non-trivial -- there were errors on newer Python versions.

• remove the python boundary for ray in scripts/populate_tox/config.py
• fix whatever problems come up

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Update: managed to fix this in the toxgen port #4810

[linear]

PY-1844 Test ray on newer Python versions