[skip ci] Refactor CIFlow init logic (#62102)
Summary:
This PR refactors the CIWorkflow post_init step to best account for how CIFlow interacts with everything.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62102
Test Plan: This PR did NOT garner any workflow changes. I ran mypy and flake8 on the changed file locally with no issues.
Reviewed By: jbschlosser
Differential Revision: D29883275
Pulled By: janeyx99
fbshipit-source-id: 6c5c1fc1878159e0de1bf8d9bd0cb32aa47af49a
