Aiuti

Change Log:
- Refactored `threadsafe_async_cache()` to internally use `asyncio.Event` in a threadsafe manor to avoid additional lock waiting threads

Change Log:
- Fixed potential for deadlocked threads when cancelling tasks using `threadsafe_async_cache()`

Change Log:
- Added a `cache` parameter to `threadsafe_async_cache` to allow providing an alternative cache object
- Added `TypeAlias`, `ParamSpec`, `ParamSpecArgs`, `ParamSpecKwargs`, and `Concatenate` to the typing module as poly-filled fallbacks
- Added generic type var `F` for any callable function
- Updated async code to use `get_running_loop()` instead of `get_event_loop()` internally
- Fixed potential threadsafety issue in `threadsafe_async_cache()` by not relying on the GIL while making locks

Change Log:
- Added `batch_timeout` configuration for `AsyncBackgroundBatcher`
- Added handling for event loop shutdown in `AsyncBackgroundBatcher` to avoid log spam
- Improved thread-safety of `ensure_aw()` and `loop_in_thread()`

Change Log:
- Added the `AsyncBackgroundBatcher` class and `async_background_batcher()` decorator
- Dropped support for Python 3.6

Change Log:
- Fixed copyright notice in LICENSE