[FTR][Ownership] Fixup test_serverless entries (elastic#195609)

## Summary

Changing lines from security-solution to other team, per request.

Contributes to: elastic#194815

Addresses:
https://github.com/elastic/kibana/pull/194819/files/d4eb7a8b397e15357790ba32a0266e724d2b775b#r1792990254

---------

Co-authored-by: Elastic Machine <[email protected]>
Co-authored-by: kibanamachine <[email protected]>

.github/CODEOWNERS

@@ -1146,8 +1146,12 @@ packages/kbn-monaco/src/esql @elastic/kibana-esql
 #CC# /x-pack/plugins/reporting/ @elastic/appex-sharedux
 #CC# /x-pack/plugins/security_solution_serverless/ @elastic/appex-sharedux
 
-### Observability Plugins
 
+# Observability UI
+/x-pack/test_serverless/api_integration/test_suites/observability/config.ts @elastic/observability-ui @elastic/appex-qa
+/x-pack/test_serverless/api_integration/test_suites/observability/index.ts @elastic/observability-ui
+
+### Observability Plugins
 
 # Observability AI Assistant
 x-pack/test/observability_ai_assistant_api_integration @elastic/obs-ai-assistant
@@ -1238,6 +1242,7 @@ x-pack/test_serverless/**/test_suites/observability/ai_assistant @elastic/obs-ai
 /x-pack/test/accessibility/apps/group3/stack_monitoring.ts @elastic/stack-monitoring
 
 # Fleet
+/x-pack/test_serverless/api_integration/test_suites/security/fleet @elastic/fleet
 /x-pack/test/fleet_packages @elastic/fleet
 /x-pack/test/fleet_api_integration @elastic/fleet
 /x-pack/test/fleet_cypress @elastic/fleet
@@ -1514,8 +1519,6 @@ x-pack/plugins/cloud_integrations/cloud_full_story/server/config.ts @elastic/kib
 /x-pack/test/rule_registry @elastic/response-ops @elastic/obs-ux-management-team
 /x-pack/test/accessibility/apps/group3/rules_connectors.ts @elastic/response-ops
 /x-pack/test/functional/es_archives/cases/default @elastic/response-ops
-/x-pack/test_serverless/api_integration/test_suites/observability/config.ts @elastic/response-ops
-/x-pack/test_serverless/api_integration/test_suites/observability/index.ts @elastic/response-ops
 /x-pack/test_serverless/functional/page_objects/svl_triggers_actions_ui_page.ts @elastic/response-ops
 /x-pack/test_serverless/functional/page_objects/svl_rule_details_ui_page.ts @elastic/response-ops
 /x-pack/test_serverless/functional/page_objects/svl_oblt_overview_page.ts @elastic/response-ops
@@ -1619,6 +1622,7 @@ x-pack/test/api_integration/apis/management/index_management/inference_endpoints
 # Security Solution
 /x-pack/test/common/services/security_solution @elastic/security-solution
 /x-pack/test/api_integration/services/security_solution_*.gen.ts @elastic/security-solution
+/x-pack/test_serverless/functional/test_suites/security/index.feature_flags.ts @elastic/security-solution
 /x-pack/test/accessibility/apps/group3/security_solution.ts @elastic/security-solution
 /x-pack/test_serverless/functional/test_suites/security/config.ts @elastic/security-solution @elastic/appex-qa
 /x-pack/test_serverless/functional/test_suites/security/config.feature_flags.ts @elastic/security-solution