Remove unused cluster provisioning services

What does this MR do and why?

Removes services that were used to provision GKE/EKS clusters until their removal in %15.0.

These changes are entirely removals, except for the two Sidekiq workers which are now a no-op (these must be removed across two releases).

This also removes ~"group::configure"'s dependence on the aws-sdk-* and google-api-client gems.

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