DEVPROD-11882: delete Parameter Store temporary logic for project vars

[Kimchelly]

DEVPROD-11882

Description

This looks long, but it's mostly copy pasting the same test data for GQL tests.

Now that all projects are migrated to use Parameter Store for project vars, we can ignore the temporary project feature flags that were used during the migration. Deleting all the temporary logic means all projects will use Parameter Store without me having to opt them into it.

• Delete all temporary logic for Parameter Store project vars. (temporary feature flags and continue on error behavior)
• Update GQL test data and smoke test set-project-var helper that were still setting project vars directly in the DB to instead use testing implementation of Parameter Store.
• Change the Parameter Store migration job to noop since it's no longer used. Once this is merged and deployed, I'll post a follow-up PR to delete it.

Testing

Existing tests all pass.