Replace or remove nest_asyncio due to lack of maintenance

[danielnsilva]

Problem

The nest_asyncio package is no longer maintained due to the author's passing nearly a year ago, which is deeply saddening. This leaves the project without updates or support, potentially leading to future issues.

Context

• There are no active forks of the nest_asyncio to take over its maintenance.
• The ARM devlib project switched from nest_asyncio to greenlet to support nested event loops.
• Python has no plans to support nested event loops, so we can't count on this approach going forward.