Investigate DISTINCT ON warning

[AetherUnbound]

We're receiving this warning in testing:

/usr/local/lib/python3.9/site-packages/flask_sqlalchemy/__init__.py:534
  /usr/local/lib/python3.9/site-packages/flask_sqlalchemy/__init__.py:534: SADeprecationWarning: DISTINCT ON is currently supported only by the PostgreSQL dialect.  Use of DISTINCT ON for other backends is currently silently ignored, however this usage is deprecated, and will raise CompileError in a future release for all backends that do not support this syntax.
    items = self.limit(per_page).offset((page - 1) * per_page).all()

This doesn't appear to be affecting anything...and I'm not sure what the workaround even is since we are using postgres 🤷‍♀️

[sea-kelp]

A lot of the sqlalchemy warnings seem to be related to the fact that we use sqlite in unit tests
https://github.com/OrcaCollective/OpenOversight/blob/main/OpenOversight/app/config.py#L64-L66