MultiTarget: Add option to disable WinUI 2.x on UWP

[Arlodotexe]

Describe the bug

Found in CommunityToolkit/Labs-Windows#438

@Arlodotexe I think your infra is injecting extra dependencies into packages, look at this:

I'm not WinUI nor the Immutable package anywhere, and they shouldn't be there. Could you take a look? 🙂

This component does not use WinUI in any way, but targets UWP. This should be added to facilitate this scenario in AppServices and other future components.

Steps to reproduce

n/a

Expected behavior

n/a

Screenshots

No response

Code Platform

• UWP
• 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 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)
• 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

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