Use explicit config loading from bin/rubocop (#33256)

db/migrate/.rubocop.yml

@@ -1,16 +0,0 @@
-inherit_from: ../../.rubocop.yml
-
-# Below are all enabled as workaround for https://docs.rubocop.org/rubocop/configuration.html#path-relativity
-# TODO: Delete this file and move above config to base naming config
-
-Rails/CreateTableWithTimestamps:
-  Include:
-    - '*.rb'
-
-Rails/ThreeStateBooleanColumn:
-  Include:
-    - '*.rb'
-
-Rails/ReversibleMigration:
-  Include:
-    - '*.rb'

db/migrate/20170112154826_migrate_settings.rb

@@ -17,7 +17,7 @@ class MigrateSettings < ActiveRecord::Migration[4.2]
       t.remove_index [:thing_type, :thing_id, :var]
       t.rename :thing_id, :target_id
       t.rename :thing_type, :target_type
-      t.column :target_id, :integer, null: false
+      t.column :target_id, :integer, null: false # rubocop:disable Rails/NotNullColumn
       t.column :target_type, :string, null: false, default: ''
       t.index [:target_type, :target_id, :var], unique: true
     end