Adding the ability to select the Dedicated fast quarantine file

What does this MR do and why?

We have implmented the ability to do a fast quarantine for those cases where a test is failing but is considered non blocking. Unfortunately the normal quarantine process involves a GitLab code change. Since Dedicated runs a version behind GitLab and only updates on major updates, it will not pickup the long term quarantines quickly.

This MR (in support of this issue and OKR) enhances how we run the fast quarantine to support a seperate quarantine file for Dedicated controlled by the environment variable RSPEC_FAST_QUARANTINE_PATH. This file was created in Add fast quarantine file for Dedicated (gitlab-org/quality/engineering-productivity/fast-quarantine!231 - merged)

MR acceptance checklist

reviewed the MR acceptance checklist, I believe this code is clean.

Screenshots or screen recordings

n/a