fix(monitoring): add temporary netpol to fix monitoring admission create job

General MR

Summary

This MR adds a temporary netpol to monitoring's values templates that fixes an issue with the admission create job starting with certain configurations.

Relevant logs/screenshots

❯ kubectl get events -n monitoring | grep job
6m18s       Normal    SuccessfulCreate             job/monitoring-monitoring-kube-admission-create                    Created pod: monitoring-monitoring-kube-admission-create-77kdh
5m46s       Normal    Completed                    job/monitoring-monitoring-kube-admission-create                    Job completed
5m24s       Normal    SuccessfulCreate             job/monitoring-monitoring-kube-admission-patch                     Created pod: monitoring-monitoring-kube-admission-patch-5jvbp
5m          Normal    Completed                    job/monitoring-monitoring-kube-admission-patch                     Job completed

Linked Issue

Closes #2867 (closed)

Upgrade Notices

N/A