fix: use fastpath for PyCapsule export when starting from pyarrow-backed Series, respect requested_schema
Follow-up to https://github.com/pandas-dev/pandas/pull/59587/files (so, I haven't added a new whatsnew)

- [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
- [ ] [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.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

@jorisvandenbossche @WillAyd fancy taking a look? Thanks for the follow up @MarcoGorelli 