py-pdm_backend: updated to 2.2.0

2.2.0

Features

Don't add '+editable' to the editable version
Custom version format for source="scm"
Fallback_version config for scm version
vendor: Update packaging to 24.0
vendors: Update pyproject-metadata to 0.8.0rc1

Bug Fixes

Change to datetime.now(tz=UTC)

Documentation

Add missing dep

Chores

Update lockfile to the latest version

(adam)