Log Message:
py-xml2rfc: updated to 3.19.1

v3.19.0

New Features
- Drop support for Python 3.7
- Add support for Python 3.12

Bug Fixes
- Deduplicate index entries
- Follow HTML presentational hints in PDF
- Remove emphasis from xref in headings and fix xrefs in headings

Documentation Changes
- update CHANGELOG.md + py file versions for v3.18.2 [skip ci]

Chores
- List required dependencies
- Get version for setup from xml2rfc source
- Update docs-publish GHA
- Update docs-publish.yml