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/docs/dev/reference/api/pandas.Series.update.html#pandas.Series.update

Documentation problem

df.update resembles how python.dict.update works, but df.update doesn't support CoW

Suggested fix for documentation

remove FutureWarning for the df.update

or create a (for example) df.coalesce method that will, actually, return something. this shouldn't brake existing code