Enable codequality backend comparison by default

This commit enables our new feature flag by default which switch our
codequality report comparison from the frontend to the backend.

changelogs/unreleased/mo-enable-cq-comparision-backend.yml

+---
+title: Enable codequality report comparison with backend
+merge_request: 54241
+author:
+type: performance

config/feature_flags/development/codequality_backend_comparison.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/300796
 milestone: '13.9'
 type: development
 group: group::testing
-default_enabled: false
+default_enabled: true