REGR: TextIOWrapper raising an error in read_csv
- [x] closes #48646
- [x] [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 [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

If `TextIOWrapper.buffer` has some more unexpected surprises, it might be worth not to use this shortcut (use src instead of src.buffer). Or only have this shortcut when pandas opens the file (edit: I went for this approach).
Thanks @twoertwein 