Update `release_evidence` feature flag yml

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/251080

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/43569

config/feature_flags/development/release_evidence.yml

 ---
 name: release_evidence
-introduced_by_url: 
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/26509
 rollout_issue_url: 
-group: 
+group: group::release management
 type: development
 default_enabled: true