[Task] Ensure support for single region Power Platform geographies

### Description

In a geography that is truly single-region (i.e. Sweden ... verify with current Microsoft documentation), a single VNet footprint would be sufficient;

Add conditional logic may be added in a future template update.

### Definition of Done

```markdown
- Conditional logic allows deploying only primary vnet resources in single-region geographies.
```

### Values Provided

- Allow the template to deployed in more geographies/regions.
- Support for Sweden which tends to have AI models before others.

No file or test is named; start by locating the deployment template's VNet resources and reviewing current Microsoft documentation for single-region geographies such as Sweden. Confirm the geography requirements, then ensure the template can deploy only primary VNet resources in those geographies and verify the deployment behavior.

Written by the indexing model from the issue text.