fix: Avoid text modification after TextChanged is raised

Fixes #6289 by removing text native TextBoxView text changes after TextChanged event is raised. This is problematic as it could cause race conditions in case the native view text changes but didn't have yet time to notify the managed code (this occurs for example on GTK).

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBox.cs

@@ -272,31 +272,35 @@ protected virtual void OnTextChanged(DependencyPropertyChangedEventArgs e)
 			}
 		}
 
+		/// <summary>
+		/// This is called asynchronously after the UI changes in line with WinUI.
+		/// Note that no further native text box view text modification should
+		/// be performed in this method to avoid potential race conditions
+		/// (see #)
+		/// </summary>
 		private void RaiseTextChanged()
 		{
-			if (!_isInvokingTextChanged)
+			if (_isInvokingTextChanged)
 			{
+				return;
+			}
+
 #if !HAS_EXPENSIVE_TRYFINALLY // Try/finally incurs a very large performance hit in mono-wasm - https://github.com/dotnet/runtime/issues/50783
-				try
+			try
 #endif
-				{
-					_isInvokingTextChanged = true;
-					TextChanged?.Invoke(this, new TextChangedEventArgs(this));
-				}
+			{
+				_isInvokingTextChanged = true;
+				TextChanged?.Invoke(this, new TextChangedEventArgs(this));
+			}
 #if !HAS_EXPENSIVE_TRYFINALLY // Try/finally incurs a very large performance hit in mono-wasm - https://github.com/dotnet/runtime/issues/50783
-				finally
+			finally
 #endif
-				{
-					_isInvokingTextChanged = false;
-					_isTextChangedPending = false;
-				}
+			{
+				_isInvokingTextChanged = false;
+				_isTextChangedPending = false;
 			}
-
-			_textBoxView?.SetTextNative(Text);
-
 		}
 
-
 		private void UpdatePlaceholderVisibility()
 		{
 			if (_placeHolder != null)

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBoxView.skia.cs

@@ -122,6 +122,7 @@ internal void UpdateTextFromNative(string newText)
 			if (textBox != null)
 			{
 				var text = textBox.ProcessTextInput(newText);
+				DisplayBlock.Text = text;
 				if (text != newText)
 				{
 					SetTextNative(text);