Draft: Repair cluster-build pipeline

The introduction of building RHEL8 images on the cluster in MR !1681 (merged) had a flaw: it would recreate image streams on every CI run, thereby losing the association to images in the image registry. In the CI, we change from time to time the ran-base image between tags develop and ci-temp. By recreating the image streams, we quickly lost the association of ran-base:develop, which the CI assumed to "just be there". In this case, most builds would fail, basically bringing the CI to a halt. The actually important change here is in 83736340

Marking as BUILD-ONLY as we cannot test this in the CI: the CI will trigger the normal RHEL8 build on asterix. I will reproduce the scenario we had previously, i.e., trigger this pipeline multiple times in a way that builds will change the ran-base image between ran-base:develop and ran-base:ci-temp. The expected outcome is to always have a successful build, of course.

@lthomas I have additional changes to not use the SSHConnection class, but this will come later. The same with the cleanup of the physims.

openshift/README.md

@@ -119,13 +119,15 @@ The `<image>` could be `oai-gnb`, and the `<tag>` `ci-temp`.
 
 # 6. Deployment using HELM Charts
 
-**CAUTION: even more experimental.**
-
-Helm charts are located in another repository:
+Helm charts are located under `charts`. Assuming that the image is in the image
+registry, the physims could be deployed as shown in the following steps:
 
 ```bash
-git clone https://github.com/OPENAIRINTERFACE/openair-k8s.git
-cd openair-k8s
-git checkout helm-deployment-S6a-S1C-S1U-in-network-18-with-enb
-helm install mme /path-to-your-cloned/openair-k8s/charts/oai-mme/
+grep -rl OAICICD_PROJECT ./charts/ | xargs sed -i -e "s#OAICICD_PROJECT#****-ran#" # select the correct project
+sed -i -e "s#TAG#ci-temp#g" ./charts/physims/values.yaml                           # select the correct tag
+helm install physim ./charts/physims/                                              # deploy
+# use any commands to inspect the pods:
+oc get pods
+oc logs <pod>
+helm uninstall physim                                                              # undeploy
 ```