💥 Enable lambda worker async configure callback

[jmaeagle99]

What was changed

• Allow lambda worker's run_worker function to accept async configure callbacks. The callback now supports synchronous functions, async functions, and async generators (or equivalently, @asynccontextmanager-decorated functions). The async generator form acts as a context manager: setup runs before the yield, and teardown runs after the worker has stopped.
• The configure callback is now invoked within an asyncio event loop so it can make async calls.
• 💥 The configure callback is now called per-invocation of the lambda worker instead of just once at startup. Configuration errors now surface as Lambda invocation errors rather than at cold start.

Why?

Support configurations that require async calls and resources that must stay alive across the worker's lifetime, such as the S3 driver client.

Checklist

1. How was this tested: Unit tests
2. Any docs updates needed? No

[Sushisource]

Just a few minor things. Thanks!