So now we know where to use the `where.missing` method which was
introduced in Rails 6.1.
Note this rule didn't detect all cases where the new method can be used.
We noticed there was a performance issue while browsing the SDG
Management section and when one of our tests started failing sometimes
because the request to the relations#index controller took too long.
The issue proved to be `SDG::Target#<=>`. This method calls `.goal` for
each target, meaning we were generating 169 database queries when
sorting all targets.
So we're comparing codes directly to minimize the number of database
queries and improve performance. Requests to the relations index take
now less than third of the time they used to take.
and its relation with relatables
Note about sdg_review factory: Cannot use the constantize method on
the relatable_type as long as the relatable classes will be loaded and
this will throw an exception because the database is not available at
factiry definition time.
Note using `params[:relatable_type].classify` is recognized as a
security risk by some tools. However, it's a false positive, since we've
added constraints to the URL so that paramenter can only have the values
we trust.
