Remove Helm 3 upgrade CI config
In !2411 (merged), we introduced a temporary config to upgrade review apps and production environment from Helm 2 to 3. We need to keep this config for a while to make sure all existing review apps can be migrated to Helm 3 by running the review:helm-2to3:migrate
manual job. Once we are confident that all review apps have been migrated or shut down, we can clean up the CI config by reverting !2411 (merged) altogether.
/cc @hfyngvason