Updated e2e cert generator image

Author: Bobbins228

config/e2e/config.yaml

@@ -7,6 +7,6 @@ data:
     kuberay:
       rayDashboardOAuthEnabled: false
       ingressDomain: "kind"
-      certGeneratorImage: quay.io/project-codeflare/ray:latest-py39-cu118
+      certGeneratorImage: quay.io/project-codeflare/ray:2.20.0-py39-cu118
     appwrapper:
       enabled: true