Generate valid self-signed TLS certificate for metrics server

The dummy certificate data (tls.crt=dummy) caused the metrics server
to crash with "tls: failed to find any PEM data in certificate input".
Generate a proper self-signed certificate using openssl so the TLS
server can start successfully.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: AnnaZivkovic

.tekton/rapidast-integration-pipeline.yaml

@@ -124,9 +124,12 @@ spec:
               CURRENT_NS=$(oc config view --minify -o jsonpath='{..namespace}')
               echo "Deploying to namespace: $CURRENT_NS"
 
-              # Create dummy TLS secret so the deployment can mount it
-              oc create secret generic multiarch-tuning-operator-controller-manager-service-cert \
-                --from-literal=tls.crt=dummy --from-literal=tls.key=dummy \
+              # Create self-signed TLS certificate for metrics server
+              openssl req -x509 -newkey rsa:2048 -nodes -days 1 \
+                -keyout /tmp/tls.key -out /tmp/tls.crt \
+                -subj "/CN=controller-manager" 2>/dev/null
+              oc create secret tls multiarch-tuning-operator-controller-manager-service-cert \
+                --cert=/tmp/tls.crt --key=/tmp/tls.key \
                 --dry-run=client -o yaml | oc apply -f -
 
               # Create ServiceAccount that the deployment references