[moodle] Remove cert-manager annotations in Ingress

```
ingress:
  enabled: true
  className: "nginx"
  annotations:
    cert-manager.io/cluster-issuer: "letsencrypt-prod"
    nginx.ingress.kubernetes.io/proxy-body-size: "512m"
  hostname: moodle.example.com
  path: /
  pathType: Prefix
  tls: []
  extraHosts: []
  extraPaths: []
  extraRules: []
```

cert-manager is not included in this install. Remove these to avoid any confusion.