DEPR: Remove pandas.datetime

[ryankarlos]

A follow up issue from #30296 , where it was discussed that pd.datetime should also be deprecated to only allow imports directly from datetime

>>> import pandas as pd
>>> pd.datetime
<class 'datetime.datetime'>

[ryankarlos]

take

[abhinavgaur]

So, only places where I need to make change in my past codes is

• add from datetime import datetime and

• replace pd.datetime with datetime ?