Merge branch 'fix-migration-record-to-not-sti' into 'master'

Disable STI behavior on `MigrationRecord`

See merge request gitlab-org/gitlab!85577

lib/gitlab/database/migration.rb

@@ -46,6 +46,7 @@ class V2_0 < V1_0 # rubocop:disable Naming/ClassAndModuleCamelCase
         # ActiveRecord::Base depending where the migration runs.
         # This helper class is provided to avoid confusion using `ActiveRecord::Base`
         class MigrationRecord < ActiveRecord::Base
+          self.abstract_class = true # Prevent STI behavior
         end
       end