This includes:

 ...
 import sqlite as final fallback on import error

 if sqlite_version in (2, 3):
    arg = '?'
 else:
    arg = '%s'


 Removing self.sqlite_busy_handler and it's invocation

look for other checks against sqlite_version and eliminate sqlite 1 cases.
Also consider removing tests that match (2, 3) and just running the code
without an if test.

This cleans up untested code that is not usable these days.

Done in changeset:   7921:e3975f679bf1

Includes deprecation section in upgrading.txt for 2.4.0.

Also added ticket to remove support for PySQLite in issue 2551343.