Bump importlib metadata version, part 2 (#154)

* Bump importlib metadata version

* Update run-tests.yml

* Update CHANGELOG.md

* Update run-tests.yml

* Fix importlib-metadata dep according to @rxm7706
<https://github.com/cruft/cruft/pull/153#issuecomment-1100861246>

* Update dependencies to try and pass safety

* Bump mkdocs to satisfy safety

* Fix some minor type-related warnings

* Switch to poetry-core

* Bump black

* black test_api.py

* Make importlib_medatata import conditional

* Assert type with bandit ignore

* Add "no cover" for 3.7 importlib_metadata import

Co-authored-by: Sambhav Kothari <sambhavs.email@gmail.com>