Make each PCS Scenario Test environment use its own branch

Currently, scenario tests use the master/main branches of the maestro-auth-test repos by default.
This recently resulted in some red tests when I was working on a new feature and writing a test for it.

To avoid this, we should have three branches:
- dev
- main
- production

and each environment would target its respective branch.

Copilot can probably take care of the code changes, but we'll need to manually create the branches

Start by locating the PCS scenario-test environment configuration and the current branch defaults for the maestro-auth-test repositories. Check how the dev, main, and production environments are selected, then create the three branches manually and verify that each environment targets its corresponding branch.

Written by the indexing model from the issue text.