Remove the useless metrics in `vm.yaml` (#6705)

CHANGES.md

@@ -76,6 +76,7 @@ Release Notes.
 * Using "service.istio.io/canonical-name" to replace "app" label to resolve Envoy ALS service name.
 * Append the root slash(/) to getIndex and getTemplate requests in ES client.
 * Fix `disable` statement not working. This bug exists since 8.0.0.
+* Remove the useless metric in `vm.yaml`.
 
 #### UI
 * Update selector scroller to show in all pages.

oap-server/server-bootstrap/src/main/resources/otel-oc-rules/vm.yaml

@@ -89,8 +89,6 @@ metricsRules:
     #node filefd
   - name: filefd_allocated
     exp: node_filefd_allocated
-  - name: filefd_maximum
-    exp: node_filefd_maximum