Remove legacy management endpoints

Author: adutra

CHANGELOG.md

@@ -31,6 +31,9 @@ request adding CHANGELOG notes for breaking (!) changes and possibly other secti
 
 ### Upgrade notes
 
+- The legacy management endpoints, `/metrics` and `/healthcheck`, were removed. Use the new endpoints instead:
+  `/q/metrics` and `/q/health`.
+
 ### Breaking changes
 
 - Helm chart: the default value of the `authentication.tokenBroker.secret.symmetricKey.secretKey` property has changed