Update CI Xcode version to 13.0 (#1536)
Update CI Xcode version to 13.0 (#1536)

Summary:
## Changes in this pull request

- Update CI Xcode version to 13.0 for testing iOS 15 compatibility

### Checklist

- [x] All tests pass. Demo project builds and runs.
- [x] I added tests, an experiment, or detailed why my change isn't tested.
- [x] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [x] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)

Pull Request resolved: https://github.com/Instagram/IGListKit/pull/1536

Reviewed By: candance

Differential Revision: D31628765

Pulled By: lorixx

fbshipit-source-id: 1583cf0e1e8df524deede1204ce1430baa39262b

Instagram/IGListKit,Instagram/IGListKit,Instagram/IGListKit,Instagram/IGListKit,Instagram/IGListKit