Instead of defining a new factory check if we could FactoryBot.modify existing factory and add the EE-specific trait

The following discussion from !105783 (merged) should be addressed:

• @splattael started a discussion:

  Suggestion (non-blocking) Instead of defining a new factory I wonder if we could FactoryBot.modify existing factory and add the EE-specific trait? 🤔

  FactoryBot.modify do
    factory :cluster_agent do