DOC: `is_interval` is deprecated, but not in the docs

[Dr-Irv]

Pandas version checks

• I have checked that the issue still exists on the latest versions of the docs on main here

Location of the documentation

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.api.types.is_interval.html

Documentation problem

This page should show that is_interval is deprecated as of v2.2.

Suggested fix for documentation

This page should show that is_interval is deprecated as of v2.2.