BUG: Fixed strange behaviour of pd.DataFrame.drop() with inplace argu…
closes  #30484

- [x] closes #xxxx
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

This is my first PR, so pardon me if I did something wrong.

To fix this issue I started by creating a failing test based on the example given by the reporter. After, I fixed the test by removing the "inplace" special methods from add_special_arithmetic_methods, following what was suggested as a comment in the code.