ARM update fails with 2023-08-01 when setting updateChannel property

Deploying Azure Cache for Redis instance with bicep template below.
The initial deployment works as expected without any issues.

Running deployment again when resource already exists results with error:
> "The unknown resource response code 'NotModified' is encountered."

Removing the line `updateChannel: 'Stable'` fixes the problem. `Stable` is the default either way.
The problem only affects version `2023-08-01` (older versions don't have this property).

```bicep
resource redis 'Microsoft.Cache/redis@2023-08-01' = {
name: 'redis-${uniqueString(resourceGroup().id)}'
location: resourceGroup().location
properties: {
sku: {
name: 'Basic'
family: 'C'
capacity: 0
}
redisConfiguration: {
'maxmemory-reserved': '30'
'maxfragmentationmemory-reserved': '30'
'maxmemory-delta': '30'
}
enableNonSslPort: false
redisVersion: '6.0'
publicNetworkAccess: 'Disabled'
minimumTlsVersion: '1.2'
updateChannel: 'Stable'
}
}
```

Start by reproducing the second deployment from the issue's Bicep template using Microsoft.Cache/redis API version 2023-08-01 and the updateChannel property. Compare the behavior with that property removed and with older API versions; done means the existing-resource deployment no longer returns the NotModified error while retaining the intended update channel.

Written by the indexing model from the issue text.