Add compatibility for the bun runtime version of Worker

First, I want to say your library has worked incredibly well for my projects. Thank you!

With the 7.0 release of bun, it now includes Worker for doing work in other threads. More info here: https://bun.sh/blog/bun-v0.7.0#concurrency-with-worker

What is the level of effort to have threads recognize this runtime and offer the worker pool logic? This will be a valuable runtime and worthwhile to support. I'm happy to help in any way I can so please let me know what I can do.