fix(circleci): now using correct project IDs, cleaned up env var names

[emaydeck-mozilla]

I was accidentally using the GAR project ID for both OIDC and GAR. I updated this workflow to:

• Use the correct values for each respective project ID
• Rename the environment variables so their scopes are clearer (GAR vs OIDC)

I already updated the corresponding environment variables on CircleCI.