Deprecate mapper argument in rename
- [x] supposed fix #44627
- [ ] 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

> CI checks are failing, can you address them please?
> 
> ```
> pandas/core/generic.py:4421: error: unused "type: ignore" comment
> pandas/core/generic.py:4485: error: unused "type: ignore" comment
> ```

Sorry, I don't know how to address failing checks, I don't know anything about CI/CD.  you can just remove those two `# type: ignore` comments

I'd suggest you read through the contributing guide in full too https://pandas.pydata.org/docs/development/contributing.html > you can just remove those two `# type: ignore` comments
> 
> I'd suggest you read through the contributing guide in full too https://pandas.pydata.org/docs/development/contributing.html

Yeah sure, Thanks for your effort. Hello @Varun270! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:









There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2021-12-02 14:57:56 UTC > you can just remove those two `# type: ignore` comments
> 
> I'd suggest you read through the contributing guide in full too https://pandas.pydata.org/docs/development/contributing.html

You can review it again I have done the changes that you suggested. > Thanks @Varun270
> 
> ![](https://camo.githubusercontent.com/202c6f2c3bb538bc8a95cd16031bf924a90b699c6b275b9d11afad929b75be1d/68747470733a2f2f692e666c756666792e63632f32374d48517047564866387a734271783936677854355042356d53316a746a442e676966)

Thanks for helping me, I learned a lot!! thanks @Varun270 