[obs] Remove NetworkConnectionsTooHigh alert

Author: Furisto

operations/observability/mixins/workspace/rules/nodes.yaml

@@ -55,15 +55,3 @@ spec:
         description: Automatic scale-up failed for some reason.
       expr: |
         increase(cluster_autoscaler_failed_scale_ups_total[1m]) != 0
-
-    - alert: NetworkConnectionsTooHigh
-      labels:
-        severity: warning
-        team: workspace
-      for: 10m
-      annotations:
-        runbook_url: https://github.com/gitpod-io/runbooks/blob/main/runbooks/NetworkConnectionsTooHigh.md
-        summary: Network connection numbers remain high for 5 minutes.
-        description: Network connection numbers remain high for 5 minutes.
-      expr: |
-        node_nf_conntrack_entries{instance=~"workspace-.*", instance!~"serv.*"} > 20000