FrameworkElementExtensions.Cursor is not available on WASDK target

### Describe the bug

As mentioned here:
https://github.com/CommunityToolkit/Windows/blob/321f5ddc8f3bf07865c8f51d992febb25fd7859a/components/Extensions/src/Element/FrameworkElementExtensions.Mouse.cs#L16
the Cursor extension was willingly disabled on WASDK targets during initial porting to v8.

However, I'm fairly sure the extension works on WASDK, as the v7 variant works without any issue.

### Steps to reproduce

```text
Try using the sample code for the Cursor extension on a WinUI3 project

```

### Expected behavior

I think the `#if !WINAPPSDK` block for this extension could be removed, making it available on v8.

### Screenshots

_No response_

### Code Platform

- [ ] UWP
- [x] WinAppSDK / WinUI 3
- [ ] Web Assembly (WASM)
- [ ] Android
- [ ] iOS
- [ ] MacOS
- [ ] Linux / GTK

### Windows Build Number

- [ ] Windows 10 1809 (Build 17763)
- [ ] Windows 10 1903 (Build 18362)
- [ ] Windows 10 1909 (Build 18363)
- [ ] Windows 10 2004 (Build 19041)
- [ ] Windows 10 20H2 (Build 19042)
- [ ] Windows 10 21H1 (Build 19043)
- [ ] Windows 10 21H2 (Build 19044)
- [ ] Windows 10 22H2 (Build 19045)
- [x] Windows 11 21H2 (Build 22000)
- [ ] Other (specify)

### Other Windows Build number

_No response_

### App minimum and target SDK version

- [ ] Windows 10, version 1809 (Build 17763)
- [ ] Windows 10, version 1903 (Build 18362)
- [ ] Windows 10, version 1909 (Build 18363)
- [ ] Windows 10, version 2004 (Build 19041)
- [ ] Windows 10, version 2104 (Build 20348)
- [ ] Windows 11, version 22H2 (Build 22000)
- [ ] Other (specify)

### Other SDK version

_No response_

### Visual Studio Version

_No response_

### Visual Studio Build Number

_No response_

### Device form factor

_No response_

### Additional context

_No response_

### Help us help you

Yes, but only if others can assist.

Beginne mit components/Extensions/src/Element/FrameworkElementExtensions.Mouse.cs bei der verlinkten Cursor-Erweiterung und untersuche die WASDK-Bedingung. Überprüfe das bereitgestellte Beispiel in einem WinUI 3-Projekt und bestätige anschließend, dass die Cursor-Erweiterung unter WASDK verfügbar ist und das Beispiel wie erwartet erstellt wird und sich wie erwartet verhält.

Vom Indexierungsmodell aus dem Issue-Text verfasst.