docs: misleading example regarding email claim

[hamza3202]

Pre-submission checklist

• I have searched existing issues and confirmed this is not a duplicate.

Description

At https://docs.kargo.io/operator-guide/security/access-controls, the example misleads by suggesting that the email claim is a string instead of list of claim values

Steps to Reproduce

Go to https://docs.kargo.io/operator-guide/security/access-controls#user-to-serviceaccount-mappings and scroll down to example

Expected Behavior

The example should be

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin
  namespace: kargo-demo
  annotations:
    rbac.kargo.akuity.io/claims: |
      {
        "sub": ["alice", "bob" ],
        "email": ["carl@example.com"],
        "groups": ["devops", "kargo-admin"]
      }

Actual Behavior

The example is

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin
  namespace: kargo-demo
  annotations:
    rbac.kargo.akuity.io/claims: |
      {
        "sub": ["alice", "bob" ],
        "email": "carl@example.com",
        "groups": ["devops", "kargo-admin"]
      }

Kargo Version

v1.9

Relevant Logs

Screenshots

No response

[fuskovic]

Both forms are actually accepted per: https://github.com/akuity/kargo/blob/main/api/rbac/v1alpha1/annotations.go#L58

We should make this clearer