Enable dast_saved_scans feature flag by default

ee/changelogs/unreleased/295252-enable-dast-saved-scans-ff.yml

+---
+title: Add ability to save and manage DAST scans
+merge_request: 53942
+author:
+type: added

ee/config/feature_flags/development/dast_saved_scans.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/295252
 milestone: '13.8'
 type: development
 group: group::dynamic analysis
-default_enabled: false
+default_enabled: true