Refactor all the specs to use `:integration` rather than `:service`

ee/spec/models/ee/integration_spec.rb

spec/factories/integrations.rb

spec/factories/usage_data.rb

spec/features/merge_request/user_sees_merge_widget_spec.rb

spec/features/profiles/chat_names_spec.rb

spec/graphql/types/projects/service_type_spec.rb

spec/helpers/auto_devops_helper_spec.rb

spec/lib/gitlab/import_export/fast_hash_serializer_spec.rb

...lib/gitlab/import_export/project/relation_factory_spec.rb

spec/lib/gitlab/integrations/sti_type_spec.rb

spec/models/integration_spec.rb

spec/models/project_spec.rb

spec/services/chat_names/authorize_user_service_spec.rb

spec/services/chat_names/find_user_service_spec.rb

spec/support/import_export/export_file_helper.rb

spec/workers/deployments/hooks_worker_spec.rb