Refactor: Move project metadata to pyproject.yaml

[glensc]

This is for tools like rye to work.

$ rye install plextraktsync                
$ rye tools list -vs
plextraktsync 0.31.12 ([email protected])
  plextraktsync

Refs:

• https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#writing-pyproject-toml
• https://packaging.python.org/en/latest/specifications/pyproject-toml/#declaring-project-metadata-the-project-table