Remove separate codeowners for system package kibana paths. (elastic#9731)

Author: lalit-satapathy

.github/CODEOWNERS

@@ -304,7 +304,6 @@
 /packages/system/changelog.yml @elastic/obs-infraobs-integrations @elastic/sec-linux-platform @elastic/sec-windows-platform
 /packages/system/data_stream/auth @elastic/sec-windows-platform
 /packages/system/data_stream/security @elastic/sec-linux-platform @elastic/sec-windows-platform
-/packages/system/kibana @elastic/elastic-agent-data-plane @elastic/kibana-visualizations
 /packages/system/manifest.yml @elastic/obs-infraobs-integrations @elastic/sec-linux-platform @elastic/sec-windows-platform
 /packages/system_audit @elastic/sec-linux-platform
 /packages/tanium @elastic/security-service-integrations