Visual Studio 2022 v17.12 does not update Binding to [ObservableProperty]

### Describe the bug

A WinUI custom control decorated with [ObservableObject] attribute will not update Bindings in the control's template for properties on property changed.

**This does work in Visual Studio 2022 v17.10!**
**This does NOT work in Visual Studio 2022 v17.12!**

Roslyn gang directed me here (https://github.com/dotnet/roslyn/issues/76470)
Issue reported in Community Toolkit can reproduce, but closed as external (https://github.com/CommunityToolkit/dotnet/issues/1011)

### Steps to reproduce the bug

1. Create a WinUI 3 Custom Control
2. Using CommunityToolkit, attribute the class [ObservableObject]
3. Create a field and attribute it [ObservableProperty]

```
[ObservableObject]
public sealed partial class CustomControl1 : Control
{
public CustomControl1()
{
this.DefaultStyleKey = typeof(CustomControl1);
}

[ObservableProperty] string _myValue = "Initial value";

[RelayCommand]
void UpdateValue()
{
MyValue = "Updated value";
}
}
```

5. In the control's template, bind to the property

```

<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:CustomControl1">
<StackPanel Spacing="16"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">

<TextBlock Text="{Binding MyValue, RelativeSource={RelativeSource TemplatedParent}}"/>

<Button Content="Update value!"
Command="{Binding UpdateValueCommand, RelativeSource={RelativeSource TemplatedParent}}"/>

</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>

```

7. Update the value of the MyValue property.

Sample application found here: Project PropertyBindingTest.sln in repo https://github.com/bjorn-malmo/bug-free-happiness/

Run the application using Visual Studio 2022 v17.10 and click the button:


Run the same application using Visual Studio 2022 v17.12 and click the button:


### Expected behavior

The Binding to update as a result of the change notification

### Screenshots

_No response_

### NuGet package version

WinUI 3 - Windows App SDK 1.6.3: 1.6.241114003

### Windows version

Windows 11 (23H2): Build 22631

### Additional context

_No response_

Start with the PropertyBindingTest.sln sample application linked in the issue and reproduce the binding behavior under Visual Studio 2022 v17.10 and v17.12. Compare the [ObservableObject], [ObservableProperty], and [RelayCommand] custom-control setup, and verify that the templated-parent binding updates after clicking the button.

Written by the indexing model from the issue text.