BUG: Fix dtypes change using replace with nullable dtypes (#40732)
- [x] closes #40732 
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry


Hello @hasan-yaman! 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 2021-04-12 18:30:53 UTC This pull request is stale because it has been open for thirty days with no activity. Please update or respond to this comment if you're still interested in working on this. @hasan-yaman can you add a release note Thanks @hasan-yaman for the PR. closing as stale. ping if you want to continue.