dry up available scopes to constants

(cherry picked from commit bbc305b1)

app/models/ci/runner.rb

@@ -12,7 +12,9 @@ module Ci
     RUNNER_QUEUE_EXPIRY_TIME = 60.minutes
     ONLINE_CONTACT_TIMEOUT = 1.hour
     UPDATE_DB_RUNNER_INFO_EVERY = 40.minutes
-    AVAILABLE_SCOPES = %w[specific shared active paused online].freeze
+    AVAILABLE_TYPES = %w[specific shared].freeze
+    AVAILABLE_STATUSES = %w[active paused online offline].freeze
+    AVAILABLE_SCOPES = (AVAILABLE_TYPES + AVAILABLE_STATUSES).freeze
     FORM_EDITABLE = %i[description tag_list active run_untagged locked access_level maximum_timeout_human_readable].freeze
 
     ignore_column :is_shared

lib/api/runners.rb

@@ -9,7 +9,7 @@ module API
         success Entities::Runner
       end
       params do
-        optional :scope, type: String, values: %w[active paused online offline],
+        optional :scope, type: String, values: Ci::Runner::AVAILABLE_STATUSES,
                          desc: 'The scope of specific runners to show'
         use :pagination
       end
@@ -22,7 +22,7 @@ module API
         success Entities::Runner
       end
       params do
-        optional :scope, type: String, values: %w[active paused online offline specific shared],
+        optional :scope, type: String, values: Ci::Runner::AVAILABLE_SCOPES,
                          desc: 'The scope of specific runners to show'
         use :pagination
       end
@@ -114,7 +114,7 @@ module API
         success Entities::Runner
       end
       params do
-        optional :scope, type: String, values: %w[active paused online offline specific shared],
+        optional :scope, type: String, values: Ci::Runner::AVAILABLE_SCOPES,
                          desc: 'The scope of specific runners to show'
         use :pagination
       end