[Ribbon] Incorrect collection change handling for Remove action

[lgztx96]

Describe the bug

Labs-Windows/components/Ribbon/src/Ribbon.cs

Line 188 in 13a9bf4

_panel.Children.Insert(e.OldStartingIndex, element);

The NotifyCollectionChangedAction.Remove branch appears to be incorrect: it inserts items into _panel.Children instead of removing them.

Steps to reproduce

See bug description above.

Expected behavior

Items should be removed from _panel.Children when a NotifyCollectionChangedAction.Remove event occurs, instead of being inserted.

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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