CI: Have dedicated Python 3.13 job instead of using Python dev
We've been testing Python 3.13 using the `Python dev` job. Since Python 3.13 has been available since last October, we should be able to test this version with a dedicated job with all of our optional dependencies. 

Additionally, this new job caught an unclosed `sqlite3` engine, so modified some `test_sql.py` tests (and removed unnecessary parametrizations)
Going to merge since green. Happy to follow up if needed