Avoid commenting SQLite library reference, imports and usage

[renaudjenny]

I commented out every references to SQLite as when I deploy on Heroku, it will lead to a crash at the compilation because sqlite driver is not available on their distant machine.

I only use SQLite for testing purpose (that accelerates the tests and avoid touching a "real" database, thanks to the app.databases.use(.sqlite(.memory), as: .sqlite) option which is amazing!).

Could be nice to avoid that, because it will slow us down when we want to test, or deploy and forget to comment out back :(.

Running a script that does the comment job for us could be fine.