chore(helm): bump ravnar chart to 0.0.11

[tylerpotts]

Pulls in ravnar chart 0.0.11, which adds extraVolumes / extraVolumeMounts passthrough on the ravnar deployment (nebari-dev/ravnar#67).

Motivation: private-CA deployments. Ravnar's OIDCTokenValidator fetches the Keycloak issuer's openid-configuration with httpx at startup and crash-loops behind a private CA (SSL: CERTIFICATE_VERIFY_FAILED). With 0.0.11 the CA can be mounted and trusted entirely through values:

ravnar:
  extraEnv:
    SSL_CERT_FILE:
      value: /etc/ssl/nebari/ca.crt
  extraVolumes:
    - name: nebari-ca
      configMap:
        name: nebari-ca
  extraVolumeMounts:
    - name: nebari-ca
      mountPath: /etc/ssl/nebari
      readOnly: true

No umbrella chart changes needed beyond the dependency bump; the values schema does not restrict extra ravnar keys.