textproc/py-python-lsp-server: Update to 1.6.0

Major release with the following new features and changes:

• Migrate to MarkupContent and convert docstrings to Markdown by default
• Add support for flake8 version 5
• Add function objects to Jedi completions
• Don't include class / functions objects by default in Jedi completions

Changelog: https://github.com/python-lsp/python-lsp-server/releases/tag/v1.6.0

Reported by: portscout, Repology