Update metadata for transition

Updates metadata for DORA pages

doc/api/dora/metrics.md

 ---
-stage: Release
-group: Release
+stage: Manage
+group: Optimize
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
 type: reference, api
 ---

doc/api/dora4_project_analytics.md

 ---
-stage: Release
-group: Release
+stage: Manage
+group: Optimize
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
 type: reference, api
 ---