8.9 changelog (#374)

* add 8.9 changelog

* update changelog entry

Author: kevinlog

package/endpoint/changelog.yml

@@ -1,8 +1,11 @@
-- version: "8.9.0-next"
+- version: "8.9.0"
   changes:
-    - description: TBD
+    - description: Fix mapping error by replacing string with keyword
+      type: bugfix
+      link: https://github.com/elastic/endpoint-package/pull/373
+    - description: ETW Threat-Intelligence API Event metrics
       type: enhancement
-      link: https://github.com/elastic/endpoint-package/pull/364
+      link: https://github.com/elastic/endpoint-package/pull/370
 - version: "8.8.0"
   changes:
     - description: change action.key.values to object in alerts