Create new ApprovalItem - error response : malformed or incorrect

Describe the bug

I submit a new approvalitem. The api response that the message are malformed or incorrect.

The body of the request looks like following json. The problem is that there is an additional odata type information.

{
    "allowEmailNotification": true,
    "approvalType": "basic",
    "approvers": [
        {
            "@odata.type": "#microsoft.graph.approvalIdentitySet",
            "user": {
                "displayName": "Alex Wilber",
                "id": "9a033c37-4b75-4a89-87f6-8cd7f5b66026"
            }
        }
    ],
    "description": "Details",
    "displayName": "Title of approval 22"
}

Expected behavior

Ignore the odata type by converting the object to a json string
"@odata.type": "#microsoft.graph.approvalIdentitySet",

How to reproduce

var requestBody = new ApprovalItem
  {
      DisplayName = "Title of approval 22",
      Description = "Details",
      ApprovalType = ApprovalItemType.Basic,
      AllowEmailNotification = true,
      AllowCancel = true,                        
      Approvers = new List<ApprovalIdentitySet>
      {
          new ()
          {
              User = new Identity
              {
                  Id = "9a033c37-4b75-4a89-87f6-8cd7f5b66026",
                  DisplayName= "Alex Wilber"
              },
          }
      }
  };
  var result = await graphBetaClient.Solutions.Approval.ApprovalItems.PostAsync(requestBody)

SDK Version

5.86.0

Latest version known to work for scenario above?

No response

Known Workarounds

Debug output

</details>


### Configuration

_No response_

### Other information

_No response_

Start with the ApprovalItem request construction and the Solutions.Approval.ApprovalItems.PostAsync entry point, then trace how Approvers is serialized into the request body. Reproduce the issue with the supplied example and verify that the generated JSON no longer includes the unwanted @odata.type field.