[Microsoft.OperationsManagement/solutions]: Plan is missing Version field, causing issues with idempotency

### Resource Type

Microsoft.OperationsManagement/solutions

### Api Version

2015-11-01-preview

### Issue Type

Missing property(s)

### Other Notes

Using the bicep shown in the bicep repro section causes this error:
> CannotUpdatePlan - Resource plan can not be changed for Resource id: '/subscriptions/REDACTED/resourceGroups/REDACTED/providers/Microsoft.OperationsManagement/solutions/REDACTED'

Adding the `version` property to the `plan` property causes no error and behaves as expected:
``` bicep
resource sqlAuditingSolution 'Microsoft.OperationsManagement/solutions@2015-11-01-preview' = {
name: 'SQLAuditing[${logWorkspaceName}]'
location: location
plan: {
name: 'SQLAuditing[${logWorkspaceName}]'
product: 'SQLAuditing'
promotionCode: ''
publisher: 'Microsoft'
version: '1.0'
}
properties: {
containedResources: [
'${logWorkspace.id}/views/SQLAccessToSensitiveData'
'${logWorkspace.id}/views/SQLSecurityInsights'
]
workspaceResourceId: logWorkspace.id
}
}
```

However, adding the `version` property does cause this error:

> REDACTED : Warning BCP037: The property "version" is not allowed on objects of type "SolutionPlan". No other properties are allowed. If this is an inaccuracy in the documentation, please report it to the Bicep Team. [https://aka.ms/bicep-type-issues]

### Bicep Repro

```bicep
resource sqlAuditingSolution 'Microsoft.OperationsManagement/solutions@2015-11-01-preview' = {
name: 'SQLAuditing[${logWorkspaceName}]'
location: location
plan: {
name: 'SQLAuditing[${logWorkspaceName}]'
product: 'SQLAuditing'
promotionCode: ''
publisher: 'Microsoft'
}
properties: {
containedResources: [
'${logWorkspace.id}/views/SQLAccessToSensitiveData'
'${logWorkspace.id}/views/SQLSecurityInsights'
]
workspaceResourceId: logWorkspace.id
}
}
```

### Confirm

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

Search the type definition for Microsoft.OperationsManagement/solutions@2015-11-01-preview and its SolutionPlan type. Compare the definition with the Bicep repro and the documented plan shape, then validate that version is accepted without the BCP037 warning and supports the shown deployment.

Written by the indexing model from the issue text.