Update .NET support to indicate continued support

[champnic]

Rendered article section for review:

• Introduction to Microsoft Edge WebView2
  • https://review.learn.microsoft.com/microsoft-edge/webview2/?branch=pr-en-us-3072#supported-platforms
  • Before/Live

AB#49090948

[learn-build-service-prod[bot]]

Learn Build status updates of commit 234462d:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/webview2/index.md	:white_check_mark:Succeeded	View

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