[BUG] Not possible to enable dynamic throttling/quota for OpenAI deployments?

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/main/specification/cognitiveservices/resource-manager/Microsoft.CognitiveServices/preview/2024-06-01-preview/cognitiveservices.json

### API Spec version

2024-06-01-preview

### Describe the bug

The Azure portal has a switch "Enable Dynamic Quota" under "Edit Deployment" for Cognitive Services Deployments.

The spec doesn't have anything called "dynamic quota". It does have property `dynamicThrottlingEnabled`, but it's only settable for CS accounts. For deployments, it (or the containing property) is marked `"readOnly": true`.

How can API clients "Enable Dynamic Quota"?

### Expected behavior

The API offers the same functionality than the portal, including "Enable Dynamic Quota".

### Actual behavior

`dynamicThrottlingEnabled` is read-only.

### Reproduction Steps

Just based on the linked API spec.

### Environment

_No response_