[Maintenance]: Migrate to psycopg3

[Mark90]

Migrate from psycopg2-binary to psycopg-binary==3.x.

Draft PR: https://github.com/workfloworchestrator/orchestrator-core/pull/1093

Problem: When using this in the SURF Orchestrator with 3 celery workers and starting multiple validation tasks, they all hang on the "Lock subscription" step. This doesn't do any actual locking, it merely updates the subscription table. But from inspecting Postgres which queries could not complete, I saw queries related to the process_steps table. I don't really have any concrete investigation hints right now.