Update PyArrow conversion and arrow/parquet tests for pyarrow 19.0
With the upcoming pyarrow 19.0, it should start returning the future default string dtype itself, which will require some (test) changes on our side. 
Thanks for tackling this. Maybe we should also have a note in our string guide about preferring PyArrow > 19 to ensure better type preservation? Merging to get the CI to green. Happy to have the doc note about Pyarrow interop in a follow up PR Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
git checkout 2.3.x
git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
git cherry-pick -x -m1 5efac8250787414ec580f0472e2b563032ec7d53
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
git commit -am 'Backport PR #60716: Update PyArrow conversion and arrow/parquet tests for pyarrow 19.0'
```

4. Push to a named branch:

```
git push YOURFORK 2.3.x:auto-backport-of-pr-60716-on-2.3.x
```

5. Create a PR against branch 2.3.x, I would have named this PR:

> "Backport PR #60716 on branch 2.3.x (Update PyArrow conversion and arrow/parquet tests for pyarrow 19.0)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the `Still Needs Manual Backport` label once the PR gets merged.

If these instructions are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 @mroeschke thanks for finishing this!

Manual backport -> https://github.com/pandas-dev/pandas/pull/60755