Tubthumper

Added
- Tubthumper now supports Python 3.12

Deprecated
- Tubthumper no longer supports Python 3.7, which has reached its end of life.

Added
- Tubthumper now supports Python 3.11
- `typing_extensions` now installed for Python versions < 3.10
- Type annotations now use `typing.ParamSpec` to annotate types of decorated functions

Changed
- Package version is now hardcoded instead of stored in a file.

Deprecated
- Tubthumper no longer supports Python 3.6, which has reached its end of life.

Changed
- Reduced overhead of retry utilities by calculating backoff incrementally

Added
- `retry` function
- `retry_decorator` function
- `retry_factory` function
- `RetryError` exception