[Service Bus Namespace Subscription]: properties.userMetadata

### Resource Type

Microsoft.ServiceBus/namespaces/topics/subscriptions

### Api Version

2024-01-01

### Issue Type

Type is unavailable

### Other Notes

Warning BCP037: The property "userMetadata" is not allowed on objects of type "SBSubscriptionProperties". Permissible properties include "clientAffineProperties", "duplicateDetectionHistoryTimeWindow", "forwardDeadLetteredMessagesTo", "status".

This property appears as a change when we do a "what-if" and do not provide a value. When we do provide a value it appears to be set on the resource, as expected.

### Bicep Repro

_No response_

### Confirm

- [x] I have read the troubleshooting guide and looked for duplicates.

Start by reproducing the warning for Microsoft.ServiceBus/namespaces/topics/subscriptions with API version 2024-01-01 and inspect the corresponding type definition. Compare behavior when userMetadata is omitted and supplied; done when the property is accepted and what-if no longer reports an erroneous change.

Written by the indexing model from the issue text.