fix(captain): retain approved FAQ suggestion sources

enterprise/app/services/captain/faq_suggestion_approval_service.rb

@@ -16,7 +16,6 @@ class Captain::FaqSuggestionApprovalService
         answer: suggestion.answer,
         status: :approved
       )
-      suggestion.observations.delete_all
       suggestion.approved!
       response
     end

spec/enterprise/controllers/api/v1/accounts/captain/faq_suggestions_controller_spec.rb

@@ -122,7 +122,7 @@ RSpec.describe 'Api::V1::Accounts::Captain::FaqSuggestions', type: :request do
       expect(response).to have_http_status(:success)
       expect(response.parsed_body['answer']).to eq('Enable it in account settings.')
       expect(suggestion.reload).to be_approved
-      expect(suggestion.observations).to be_empty
+      expect(suggestion.observations.pluck(:conversation_id)).to contain_exactly(conversation.id)
     end
 
     it 'lets an agent approve an accessible suggestion' do