Add more fleet release notes redirects (#2952)

Related to #2818

Adds more Fleet/Elastic Agent release notes redirects that account for
the `path_prefix` used in `navigation.yml` in docs-builder (and the [old
URL
prefix](https://github.com/elastic/docs-builder/pull/1830/files#diff-d014d789ee176611c685a20fa11c33373fb72cae6711b431a0ab961881a80b94L86)
and [new URL
prefix](https://github.com/elastic/docs-builder/pull/1830/files#diff-d014d789ee176611c685a20fa11c33373fb72cae6711b431a0ab961881a80b94R89)).

Author: colleenmcginnis

docset.yml

@@ -272,10 +272,7 @@ subs:
   observability:   "Observability"
   api-query-parms-title:   "Query parameters"
   api-examples-title:   "Examples"
-  agent-issue:   "https://github.com/elastic/elastic-agent/issues/"
   agent-pull:   "https://github.com/elastic/elastic-agent/pull/"
-  fleet-server-issue:   "https://github.com/elastic/fleet-server/issues/"
-  fleet-server-pull:   "https://github.com/elastic/fleet-server/pull/"
   es-pull:   "https://github.com/elastic/elasticsearch/pull/"
   kib-pull:   "https://github.com/elastic/kibana/pull/"
   eck_helm_minimum_version: "3.2.0"

redirects.yml

@@ -337,7 +337,14 @@ redirects:
 # Related to https://github.com/elastic/docs-content/pull/2745
   'solutions/search/run-elasticsearch-locally.md': 'deploy-manage/deploy/self-managed/local-development-installation-quickstart.md'
 
+# Related to https://github.com/elastic/docs-content/pull/2818
+# Redirects files internally
   'release-notes/fleet-elastic-agent/index.md': 'fleet-server://release-notes/index.md'
   'release-notes/fleet-elastic-agent/breaking-changes.md': 'fleet-server://release-notes/breaking-changes.md'
   'release-notes/fleet-elastic-agent/deprecations.md': 'fleet-server://release-notes/deprecations.md'
-  'release-notes/fleet-elastic-agent/known-issues.md': 'fleet-server://release-notes/known-issues.md'
+  'release-notes/fleet-elastic-agent/known-issues.md': 'fleet-server://release-notes/known-issues.md'
+# Redirects `path_prefix`
+  'release-notes/fleet/index.md': 'fleet-server://release-notes/index.md'
+  'release-notes/fleet/breaking-changes.md': 'fleet-server://release-notes/breaking-changes.md'
+  'release-notes/fleet/deprecations.md': 'fleet-server://release-notes/deprecations.md'
+  'release-notes/fleet/known-issues.md': 'fleet-server://release-notes/known-issues.md'