Enhance typing with Self to support subclassing for multiple Python versions

[mghotz]

…ersions

Pull Request Checklist

Thank you for taking the time to improve Arrow! Before submitting your pull request, please check all appropriate boxes:

• 🧪 Added tests for changed code.
• 🛠️ All tests pass when run locally (run tox or make test to find out!).
• 🧹 All linting checks pass when run locally (run tox -e lint or make lint to find out!).
• 📚 Updated documentation for changed code.
• ⏩ Code is up-to-date with the master branch.

If you have any questions about your code changes or any of the points above, please submit your questions along with the pull request and we will try our best to help!

Description of Changes

This PR enhances type hints in the Arrow library by using Self to support subclassing, ensuring compatibility with both Python 3.11 and earlier versions. The following changes were made:

Conditional Import: Imported Self from typing_extensions for Python versions below 3.11.
Updated Method Signatures: Modified methods in the Arrow class to return Self.
Type Casting: Used cast to handle type hinting where necessary.

Testing:
All existing tests were run and passed successfully, ensuring no breaking changes were introduced.

Issue:
Fixes Issue #1168.

Please review and merge this PR to improve the code's robustness and maintainability.

[jadchaar]

Thanks for the contribution. Added a comment.

I also approved the workflow for a test run.

[jadchaar]

Shouldn't this be added to requirements for 3.11 and below?

https://github.com/arrow-py/arrow/tree/master/requirements

[jadchaar]

A recent PR was merged to remove typing extensions for 3.8 and below. Mind rebasing this CR against the change and updating the requirements.txt to only pull it in for 3.9 and 3.10

reference PR - #1176