BUG: fix categorical comparison with missing values (#26504 )
- [x] closes #26504
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

This PR fixes issues comparison of ordered categorical with missing values evaluates to True(#26504 ).  Now making comparison with missing values always gives False. The missing values could be introduced when constructing a Categorical with values that don't fall in with the categories provided. 