How to update notification‐utils

1. Bump the version number in pyproject.toml (under [tool.poetry])
2. Update waffles: https://github.com/cds-snc/notification-utils/blob/main/.github/actions/waffles/requirements.txt
3. Push up your changes and do a PR review / merge as normal
4. Tag the merge commit with your new version:
   1. Checkout / update main
   2. Example: git tag -a 42.0.0 -m "42.0.0"
5. Push up the tag:
   1. git push origin --tags
6. Update pyproject.toml in notification-admin and notification-api with the new notification-utils version number