Reduce phone verification rate-limit threshold

lib/gitlab/application_rate_limiter.rb

@@ -52,8 +52,8 @@ def rate_limits # rubocop:disable Metrics/AbcSize
           project_testing_integration: { threshold: 5, interval: 1.minute },
           email_verification: { threshold: 10, interval: 10.minutes },
           email_verification_code_send: { threshold: 10, interval: 1.hour },
-          phone_verification_send_code: { threshold: 10, interval: 1.day },
-          phone_verification_verify_code: { threshold: 10, interval: 1.day },
+          phone_verification_send_code: { threshold: 5, interval: 1.day },
+          phone_verification_verify_code: { threshold: 5, interval: 1.day },
           namespace_exists: { threshold: 20, interval: 1.minute },
           update_namespace_name: { threshold: -> { application_settings.update_namespace_name_rate_limit }, interval: 1.hour },
           fetch_google_ip_list: { threshold: 10, interval: 1.minute },