Fix __ne__ for different datetime types

[mobinghoveoud]

fix #163

Description of Changes

The __ne__ function in jdatetime.datetime was implemented using __eq__ (return not self.__eq__(other_datetime)), ensuring proper handling of comparisons with datetime.datetime. This fix correctly returns True for unequal types, and tests were added to validate the behavior.

If there are any issues or areas for improvement, please feel free to let me know.
Thanks.

[mobinghoveoud]

Can this be released with v5.1.1?

[5j9]

Suggestion: There are two definitions of __ne__, one for date and one for datetime class. They are buggy; removing both should resolve the issues. (Python's default behavior is to fall back to __eq__ when __ne__ is not defined.) This approach will reduce code duplication and prevent future errors, in my opinion.

[mobinghoveoud]

Thanks @5j9 for your great suggestion! I didn’t implement the __ne__ method in the #159 for that reason, but I missed its implementation in the date class.
This method has now been removed from both classes.

[slashmili]

Thanks @mobinghoveoud 🎉 !