Add milestone to `vulnerability_finding_replace_metadata`

Based on rollout: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/66868

config/feature_flags/development/vulnerability_finding_replace_metadata.yml

@@ -2,6 +2,7 @@
 name: vulnerability_finding_replace_metadata
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/66868
 rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/337253
+milestone: '14.2'
 group: group::threat insights
 type: development
-default_enabled: false
\ No newline at end of file
+default_enabled: false