Fix cyclic definition in graphql GroupType

What does this MR do and why?

Fixes cyclic definition error when trying to individually run bin/rspec spec/graphql/resolvers/timelog_resolver_spec.rb

An error occurred while loading ./spec/graphql/resolvers/timelog_resolver_spec.rb.
Failure/Error:
  field :groups, ::Types::GroupType.connection_type, null: true,
                                                     description: 'Groups the runner is associated with. For group runners only.'

NameError:
  uninitialized constant Types::GroupType
  Did you mean?  GroupTree

Somewhat relates to #375732 (closed) See also !84202 (merged)

Screenshots or screen recordings

How to set up and validate locally

bin/rspec spec/graphql/resolvers/timelog_resolver_spec.rb should now run

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