Missing `loki_azure_blob_request_duration_seconds_bucket` Metric in Azure Storage Setup

[Caroline132]

Describe the bug
In the loki-mixin Operational dashboard, there's a section for Azure Blob (see screenshot below).
We configured storage with Azure, but the metric loki_azure_blob_request_duration_seconds_bucket does not appear to be exposed. Could you please clarify why this metric is missing even though storage is configured with Azure?

To Reproduce
Steps to reproduce the behavior:

1. Started Loki (3.5.7) with Azure storage configured through helm values. Here are the values we configured:

loki:
  storage:
    use_thanos_objstore: true
    object_store:
      type: azure
      azure:
        account_key: ${AZURE_ACCOUNT_KEY}
        account_name: ${AZURE_ACCOUNT_NAME}
        container_name: lokicontainer
        max_retries: 3
    bucketNames:
      chunks: chunks
      ruler: ruler
      admin: admin
    type: azure
    azure:
      account_key: ${AZURE_ACCOUNT_KEY}
      account_name: ${AZURE_ACCOUNT_NAME}

3. Deploy loki-mixin dashboard
4. Go to the Operational dashboard and look at the Azure Blob section

Expected behavior
Have metric working or dashboard updated with proper metric.

Environment:

• Infrastructure: Kubernetes
• Deployment tool: helm

Screenshots, Promtail config, or terminal output