[AVM Module Issue]: app-configuration failed to deploy when sku changed from Developer to Standard

### Check for previous/existing GitHub issues

- [x] I have checked for previous/existing GitHub issues

### Issue Type?

Bug

### Module Name

avm/res/app-configuration/configuration-store

### (Optional) Module Version

0.9.2

### Description

The module created app config with sku = 'Developer'.
When I wanted to upgrade to 'Standard' it fails with error

`The property 'SoftDeleteRetentionInDays' is not valid. The soft delete retention period cannot be modified. (Code:InvalidProperty)`

```bicep
param sku string

module appConfig 'br/public:avm/res/app-configuration/configuration-store:0.9.2' = {
name: '${deployment().name}-appconfig'
scope: resourceGroup(subscriptionId, effectiveResourceGroupName!)
dependsOn: [rg]
params: {
location: location
name: 'riki-config-appcs-prod2'
sku: sku
softDeleteRetentionInDays: 7
}
}
```

### (Optional) Correlation Id

_No response_