refactor(util/sync): deprecate asyncio aliases

[bssyousefi]

Summary of Changes

Deprecating two asyncio aliases (create_task and get_running_loop) used in Falcon.

Related Issues

Fixes #2253

Pull Request Checklist

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• [ ] Applied changes to both WSGI and ASGI code paths and interfaces (where applicable).
• [ ] Added tests for changed code.
• [ ] Prefixed code comments with GitHub nick and an appropriate prefix.
• [x] Coding style is consistent with the rest of the framework.
• [ ] Updated documentation for changed code.
  • [ ] Added docstrings for any new classes, functions, or modules.
  • [ ] Updated docstrings for any modifications to existing code.
  • [ ] Updated both WSGI and ASGI docs (where applicable).
  • [ ] Added references to new classes, functions, or modules to the relevant RST file under docs/.
  • [ ] Updated all relevant supporting documentation files under docs/.
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PR template inspired by the attrs project.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (cbca63d) to head (864b233).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2254 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 63 63 Lines 6852 6849 -3 Branches 1260 1260 ========================================= - Hits 6852 6849 -3 ```

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