Per our deprecation policy.

Fix #13893.

The doc build fails. I tried to update sphinx but still fails. Can't reproduce locally. Not sure if it's due to this PR. I'll submit the sphinx upgrade separately to see.

WARNING: error while formatting arguments for pytest.PytestUnraisableExceptionWarning: list index out of range [autodoc]

OK, so it's really something in this PR that's causing this sphinx error, but the only change is "9" -> "10", pretty strange. I'll look into it. Maybe switching the docs job/RTD to 3.14 will help.