Fix URL

Author: lcawl

docs/en/install-upgrade/release-notes/release-notes-fleet-agent.asciidoc

@@ -9,15 +9,15 @@
 :fleet-server-issue: https://github.com/elastic/fleet-server/issues/
 :fleet-server-pull: https://github.com/elastic/fleet-server/pull/
 
-[[release-notes-fleet-agent-9.0.0-beta1]]
+[[release-notes-fleet-agent-9.0.0]]
 = {fleet} and {agent} Release notes
 ++++
 <titleabbrev>{fleet} and {agent}</titleabbrev>
 ++++
 
 This section summarizes the changes in each release.
 
-* <<release-notes-9.0.0-beta1>>
+* <<release-notes-fleet-agent-9.0.0-beta1>>
 
 Also see:
 
@@ -26,7 +26,7 @@ Also see:
 
 // begin 9.0.0-beta1 relnotes
 
-[[release-notes-9.0.0-beta1]]
+[[release-notes-fleet-agent-9.0.0-beta1]]
 == {fleet} and {agent} 9.0.0-beta1
 
 Review important information about the {fleet} and {agent} 9.0.0-beta1 release.

docs/en/install-upgrade/release-notes/release-notes.asciidoc

@@ -6,7 +6,7 @@ This section summarizes the changes in the {stack} releases.
 * <<release-notes-beats-9.0.0>>
 * <<release-notes-security-9.0.0-beta1>>
 * <<release-notes-elasticsearch-9.0.0-beta1>>
-* <<release-notes-fleet-agent-9.0.0-beta1>>
+* <<release-notes-fleet-agent-9.0.0>>
 * <<release-notes-kibana-9.0.0-beta1>>
 * <<release-notes-logstash-9.0.0-beta1>>