AZ Cli returns debug info before result from Azure

> ### `az feedback` auto-generates most of the information requested below, as of CLI version 2.0.62

**Describe the bug**
AZ Cli returns additional output in addition to results from Azure what makes json decode more difficult on client side (for example in python code).

**To Reproduce**
1. Install AZ Cli version at least 2.28.0.
2. Run az sql server update --assign_identity --resource-group --name
3. On output first line of result is:

{'additional_properties': {}, 'user_assigned_identities': None, 'principal_id': None, 'type': 'SystemAssigned', 'tenant_id': None}

and then json representing azure resource.

**Expected behavior**
The first line shouldn't appear.

**Environment summary**
azure-cli 2.29.0

core 2.29.0
telemetry 1.0.6

Extensions:
azure-devops 0.18.0
automation 0.1.0
datafactory 0.1.0
log-analytics 0.2.1
databricks 0.7.1
subscription 0.1.4

**Additional context**
Nothing to add.