AzureDataFactoryClient uses rejected 2017 preview API version

## Description

`AzureDataFactoryClient.ListSubscriptionsAsync` in `Azure.Connectors.Sdk` 0.14.0-preview.1 generates this connector request:

```text
GET /subscriptions?x-ms-api-version=2017-09-01-preview
```

The live Azure Data Factory connector rejects that request with HTTP 400:

```text
InvalidApiVersionParameter: The api-version '2017-09-01-preview' is invalid.
```

The current supported version list returned by ARM starts with `2026-06-01`, `2025-04-01`, and other active versions; it does not include `2017-09-01-preview`.

## Source

`src/Azure.Connectors.Sdk/Generated/AzureDataFactoryExtensions.cs`

The stale version appears on `ListSubscriptionsAsync` and the other generated Data Factory management paths.

## Validation

- Package: `Azure.Connectors.Sdk` 0.14.0-preview.1
- Client: `AzureDataFactoryClient`
- Connection: authenticated Connector Namespace Azure Data Factory connection
- Result: generated client reaches the connector, which returns HTTP 400 before any data is returned

This was found while adding deployed end-to-end coverage for the 0.14 samples update.

Authored with [Dobby](https://aka.ms/dobby).

Start in src/Azure.Connectors.Sdk/Generated/AzureDataFactoryExtensions.cs at ListSubscriptionsAsync, then inspect the other generated Data Factory management paths for the rejected API version. Confirm the requests use a supported version and run the deployed end-to-end coverage mentioned in the issue to verify the connector no longer returns HTTP 400.

Written by the indexing model from the issue text.