Resource tags referencing a parameter which is a user-defined data type containing properties with optionality marker yields BCP321.

**Bicep version**
Bicep CLI version 0.30.3

**Describe the bug**
A parameter is declared as a user-defined data type containing properties that are string literals with or without a union type and an optionality marker. When this parameter is referenced by the tags property of a resource declaration the BCP321 warning is displayed for each property with an optionality marker.

**To Reproduce**
Steps to reproduce the behavior:

`main.bicep`

```bicep
targetScope = 'subscription'

type Tags = {
stringLiteral: string
stringLiteralUnionType: ('foo' | 'bar')
stringLiteralOptionalityMarker: string?
stringLiteralUnionTypeOptionalityMarker: ('foo' | 'bar')?
}

param name string
param location string
param tags Tags

resource rg 'Microsoft.Resources/resourceGroups@2024-07-01' = {
name: name
location: location
tags: tags
}
```

```
Expected a value of type "string" but the provided value is of type "null | string".
Expected a value of type "string" but the provided value is of type "'bar' | 'foo' | null".
```

**Additional context**
This issue has only arisen since upgrading to version 0.30.3 of Bicep.