Microsoft.Storage/storageAccounts: Read-Only property set in the documentation

### Resource Type

Microsoft.Storage/storageAccounts

### Api Version

2023-01-01

### Issue Type

Property(s) inaccurately marked read-only/write-only

### Other Notes

I'm currently following the `Advanced Bicep` learning path, and in the `Extend Bicep and ARM templates using deployment scripts` module unit 3 (Exercise - Add a deployment script to an ARM template), when using `Bicep + CLI`, there's a little error on the template.
I'm not quite sure if it will block the deployment or not, but the VSCode extension spits out the following error:
`The property "tier" is read-only. Expressions cannot be assigned to read-only properties.`

I was working with the example template given at step 4 of the exercise here: [Exercise - Add Deployment Scripts](https://learn.microsoft.com/en-us/training/modules/extend-resource-manager-template-deployment-scripts/3-exercise-add-deployment-script?pivots=bicepcli)

### Bicep Repro

```bicep
var storageAccountName = 'storage${uniqueString(resourceGroup().id)}'
var storageBlobContainerName = 'config'

param location string = resourceGroup().location

resource storageAccount 'Microsoft.Storage/storageAccounts@2023-01-01' = {
name: storageAccountName
tags: {
displayName: storageAccountName
}
location: location
kind: 'StorageV2'
sku: {
name: 'Standard_LRS'
tier: 'Standard'
}
properties: {
encryption: {
services: {
blob:{
enabled: true
}
}
keySource: 'Microsoft.Storage'
}
supportsHttpsTrafficOnly: true
}

resource blobService 'blobServices' existing = {
name: 'default'
}
}

```

### Confirm

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

Start by reproducing the VS Code diagnostic with the Bicep template from the linked deployment-scripts exercise, focusing on Microsoft.Storage/storageAccounts@2023-01-01 and sku.tier. Locate the corresponding resource type definition in this repository and correct its read-only metadata, then verify that the diagnostic no longer appears.

Written by the indexing model from the issue text.