PostgreSQL 14 changed the default to be scram-sha-256, so we should stop
recommending the user to use md5 or even worse password.

Suggested-By: Daniel Westermann
Author: Jonathan S. Katz
Backpatch-through: 14
Discussion: https://postgr.es/m/GV0P278MB0419A8BAC0B0B84AFA5263D9D2DC9@GV0P278MB0419.CHEP278.PROD.OUTLOOK.COM