text: Title: Add support for Python 3.11 (& 3.12)
  Body: **Is your feature request related to a problem? Please describe.**
  
  We're already running stanza on Python 3.11 and are planning to move to 3.12 as soon as torch supports it.  Would be nice if both versions could be officially supported.
  
  **Describe the solution you'd like**
  
  Ensure that stanza works on Python 3.11 & 3.12 and add a [trove classifier](https://github.com/stanfordnlp/stanza/blob/04bfef95a8e027e8d6b50f481a1917ba4d4c31af/setup.py#L63-L68).
  
  **Describe alternatives you've considered**
  
  None
  
  **Additional context**
  
  - Works for our use case on Python 3.11 without issues.
  - For Python 3.12 you probably want to wait until torch has published wheels.  (This might take a while.)
  - You could also drop support for Python [3.6](https://peps.python.org/pep-0494/#lifespan) & [3.7](https://peps.python.org/pep-0537/#lifespan) if you like.  Both reached their end-of-life a while ago.