[MPG][Diff] unused model `ArmOperationStatus` of SDK generated from typespec

[msyyc]

Compared with SDK between typespec and swagger, typespec version has unused model ArmOperationStatus.

It shall be caused by https://github.com/Azure/typespec-azure/blob/bb338afd7c124c586d4c105475cdb3da1b216b17/packages/typespec-azure-resource-manager/lib/responses.tsp#L92-L98

[msyyc]

Caused by TCGC Azure/typespec-azure#836