Increase ephemeral cluster timeout and use OpenShift 4.20

Increase cluster provisioning timeout from 30m to 60m to allow enough
time for Hypershift AWS cluster creation, which typically takes 40-60
minutes to complete.

Also upgrade to OpenShift 4.20 (current stable version) from 4.17.

Fixes: error: timed out waiting for the condition on clustertemplateinstances

Author: AnnaZivkovic

.tekton/rapidast-integration-pipeline.yaml

@@ -51,11 +51,11 @@ spec:
               - name: eaasSpaceSecretRef
                 value: $(tasks.provision-space.results.secretRef)
               - name: version
-                value: "4.17"
+                value: "4.20"
               - name: instanceType
                 value: m6g.xlarge
               - name: timeout
-                value: 30m
+                value: 60m
 
     - name: deploy-and-scan
       params: