Refs #37678 - Update evr migration to use DSL

[sjha4]

What are the changes introduced in this pull request?

The evr migration was using SQL to drop the extension possibly causing privilege issues in EL8 upgrade pipeline in nightlies.

Considerations taken when implementing this change?

What are the testing steps for this pull request?

To test new installs, run bundle exec rails katello:reset To test upgrades: You could follow this on the dev box: git reset --hard 8fed606fdc2bcd783a8e875aef43273e686c80e5 bundle exec rails katello:reset Create and sync a repo to test data migration. You could also have some host registered to test data migration on installed_packages table git checkout this branch run db:migrate and make sure everything works normally.