Fix an older type hint now revealed to be slightly wrong

Cut 3.0.3

Revert "Enhance @task's return value type hint"

Cut 3.0.2

Changelog updates

Version bump

Enhance @task's return value type hint

Fix Promise.__repr__

Cut 3.0.1

Changelog re: recent tweaks

Tell typecheckers that Promise is a context manager

ruff!

Fix some inaccuracies/display issues in wrapper-tasks docs

Explicitly document Promise.runner

Gack, somehow did not changelog the very important Py<3.9 thing.