Fixes jupyter installation randomly failing

Disables jupyter prepuller to avoid Helm chart to await for upgrading
the jupyter hub images that are used by the hub pod to spawn user pods
arrives on the nodes where users can spawn first.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/58927

changelogs/unreleased/58927-jupyterhub-fails-to-install.yml

+---
+title: Fixes jupyter installation randomly failing
+merge_request: 26126
+author:
+type: fixed

vendor/jupyter/values.yaml

@@ -23,3 +23,7 @@ ingress:
  annotations:
    kubernetes.io/ingress.class: "nginx"
    kubernetes.io/tls-acme: "true"
+
+prePuller:
+  hook:
+    enabled: false