Remove stub_const as it’s in master now

doc/api/graphql/reference/index.md

@@ -51,6 +51,8 @@ An emoji awarded by a user.
 
 ## Board
 
+Represents a project or group board
+
 | Name  | Type  | Description |
 | ---   |  ---- | ----------  |
 | `id` | ID! | ID (global ID) of the board |

spec/requests/api/graphql/namespace/projects_spec.rb

@@ -32,9 +32,6 @@ describe 'getting projects' do
   end
 
   before do
-    # we don't care how many SQL queries the spec takes
-    stub_const("Gitlab::QueryLimiting::Transaction::THRESHOLD", 1000)
-
     group.add_owner(user)
   end