DOC: Remove references to AxesSubPlot

[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/docs/dev/reference/api/pandas.core.groupby.SeriesGroupBy.hist.html (and other places)

Documentation problem

AxesSubplot was removed from matplotlib, so we need to remove it from our docs.

See matplotlib/matplotlib#18222

Suggested fix for documentation

Change the type from AxesSubplot in the docs to Axes

[Dr-Irv]

Also, the xlabelsize and ylabelsize arguments can be float or str, so types and docs have to change. These are converted to matplotlib font sizes which can be float or str

[manlattan]

@Dr-Irv Can I get this issue? I would like to work on this issue!

[luke396]

Friendly reminder, @manlattan! To address the issue, simply comment 'take,' and the issue will be automatically assigned to you. Feel free to begin resolving it at your convenience.

[manlattan]

take

[manlattan]

@luke396 Thank you!