[K8S][HELM] Update default Kyuubi version to 1.12.0

[dnskr]

Why are the changes needed?

Default Kyuubi version used in the Helm chart should be aligned with the latest release version.

How was this patch tested?

Render the chart templates to ensure 1.12.0 version is used.

helm template kyuubi charts/kyuubi

Output (reduced)

# Source: kyuubi/templates/kyuubi-statefulset.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: kyuubi
  labels:
    ...
    app.kubernetes.io/version: "1.12.0"
spec:
  template:
    ...
    spec:
      serviceAccountName: kyuubi
      containers:
        - name: kyuubi-server
          image: "apache/kyuubi:1.12.0"
          imagePullPolicy: IfNotPresent
          ...

Was this patch authored or co-authored using generative AI tooling?

No