DEPR: Remove literal string input for read_xml
- [X] closes #53767 
- [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] 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.

@mroeschke PR is ready for review! @mroeschke Pinging on green! I added multiple checks from common.py rather than just checking for `\n` 😅  @mroeschke Pinging on green @mroeschke warning logic moved to `_parse`. Pinging on green Thanks again @rmhowe425 