TST:  Add test for `numpy.maximum` with `Timestamp` and `Series` of `datetime64`
- [x] closes #50864 
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit)

Added new test to make sure `numpy.maximum` on `Timestamp` and `Series` of `datetime64` works correctly and does not fail with `TypeError`.
CI failures here may get fixed after https://github.com/pandas-dev/pandas/pull/59329 Thanks @Tirthraj93 