fix: Remove deprecated get_event_loop() in favour of alternative methods

[Revnoplex]

Summary

get_event_loop() is deprecated. All instances should be replaced in favour of get_running_loop() and whatever other alternative.

Information

• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed).
• This PR is not a code change (e.g. documentation, README, typehinting,
  examples, ...).

Checklist

• I have searched the open pull requests for duplicates.
• If code changes were made then they have been tested. (currently in progress. 4/7 files tested...)
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why.
• I have updated the changelog to include these changes.

[Revnoplex]

ah, for some reason the changes broke ext.tasks. I'm not sure why

[Revnoplex]

For some reason the behaviour of replacing get_event_loop with new_event_loop in Client causes create_tasks in tasks.py to never run

[Revnoplex]

new_event_loop is no good. Using get_event_loop_policy().get_event_loop() instead per https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.get_event_loop and python/cpython#93453

[Revnoplex]

This is getting too complicated. I'm closing this.