[Utilization] Reduce the number of specs using VCR

Proposal

Original issue: #7342 (closed)

This issue tracks efforts to reduce the number of VCRs used in non-feature tests.

The table below shows the folders in spec/fixtures/vcr_cassettes which have recorded cassettes for non-feature tests and the spec file related to it. The goal is to add stubbing to spec files mentioned below so that the related VCR folder can be removed. In the end, only feature tests should be using VCR cassettes.

VCR cassette folders	Related spec file
api_paymentmethodscontroller	spec/controllers/api/payment_methods_controller_spec.rb
gitlab_namespaces_listservice	spec/services/gitlab/namespaces/list_service_spec.rb
gitlab_namespaces_updateplaninfoservice	spec/services/gitlab/namespaces/update_plan_info_service_spec.rb
license	spec/models/license_spec.rb
mutations_temporaryextensions_create	spec/requests/api/graphql/mutations/temporary_extensions/create_spec.rb
selfservice_subscriptions_updateservice	spec/services/self_service/subscriptions/update_service_spec.rb
subscriptions	spec/controllers/subscriptions_controller_spec.rb
subscriptionscontroller	spec/controllers/subscriptions_controller_spec.rb
zuora_orders_ordermanagerservice	spec/services/zuora/orders/order_manager_service_spec.rb