update readme and version release notes (#6)

Author: bavneetsingh16

src/k8s-extension/HISTORY.rst

@@ -10,7 +10,6 @@ Release History
 1.6.5
 ++++++++++++++++++
 * microsoft.dataprotection.kubernetes: Add support for 'DisableInformerCache' configuration.
-* microsoft.azuremonitor.containers.metrics: Simplify logic and enable correct recording rule groups for managed prom extension
 
 1.6.4
 ++++++++++++++++++