Fix formatting error in the 9.0.2 release notes (#1509)

This PR fixes a formatting error in the 9.0.2 fleet & agent release
notes. No content changes beyond the correction were made.

Author: alexandra5000

release-notes/fleet-elastic-agent/index.md

@@ -30,8 +30,6 @@ To check for security updates, go to [Security announcements for the Elastic sta
 
 ### Features and enhancements [fleet-elastic-agent-9.0.2-features-enhancements]
 
-fleet-server::
-
 * Updates Go version to v1.24.3 in {{fleet}} [#4891]({{fleet-server-pull}}4891)
 
 * Updates Go version to v1.24.3 in {{agent}} [#8109]({{agent-pull}}8109)