Fix several typos under pandas/_libs
- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit) for how to run them
- [ ] whatsnew entry

Would it make sense to enable codespell for more than just these file types?
https://github.com/pandas-dev/pandas/blob/c30afb23dfa948e3b34b4d71abb16ce455012428/.pre-commit-config.yaml#L19 > 
> 
> Would it make sense to enable codespell for more than just these file types?
> 
> https://github.com/pandas-dev/pandas/blob/c30afb23dfa948e3b34b4d71abb16ce455012428/.pre-commit-config.yaml#L19

Perhaps, but it could easily lead to false-positives. Thanks @PApostol. Might be worthwhile opening up a new issue to discuss expanding the codespell check. 