Revise development release checklist document for new processes

[jathanism]

Proposed Changes

Revise the "release checklist" at docs/development/release-checklist.md to account for the following (at a minimum):

• We are using poetry and pyproject.toml now to manage packaging and dependencies
• As a result, updating the version is done using poetry version {new_version}
• Updating dependent libraries and the poetry.lock where versions are pinned is done using poetry update
• The steps taken to follow the "git flow-like" pattern we're using
  • Cutting a develop-{version} branch from develop to update release notes, bump version, etc.
  • Submitting a PR from develop-{version} back into develop (1 approval)
  • Submitting a PR from develop into main (2 approvals required)
• The new release must published to PyPI using poetry publish

Justification

Since we've changed the way Nautobot is packaged, deployed, and configured compared to its ancestor NetBox, we need to revise the release checklist for the new world.