Remove cop disable comment and preload of associations

We can just use the auto generated enum methods instead of querying the
vulnerability feedbacks manually.
Also we are not using any of the preloaded associations in this finder
so loading them into memory is just waste of resources.

ee/app/finders/security/pipeline_vulnerabilities_finder.rb

@@ -113,10 +113,10 @@ module Security
 
     def dismissal_feedback_by_fingerprint
       strong_memoize(:dismissal_feedback_by_fingerprint) do
-        pipeline.project.vulnerability_feedback
-          .with_associations
-          .where(feedback_type: 'dismissal') # rubocop:disable CodeReuse/ActiveRecord
-          .group_by(&:project_fingerprint)
+        pipeline.project
+                .vulnerability_feedback
+                .for_dismissal
+                .group_by(&:project_fingerprint)
       end
     end