Can't compile under linux_x86_64 with dynamic type in ObservableProperty

### Describe the bug

I'm trying to compile a C# Avalonia crossplatform project on Linux that uses the MVVM Community Toolkit. The project compiles and runs fine on Windows, but on Linux I'm getting a compilation error with the following line of code:

```csharp
[ObservableProperty]
private dynamic _selectedDevice = null!;
```
The program compiles without errors on Windows, even when I target Linux as the runtime. However, when I transfer the compiled program to a Linux machine and try to run it, it fails with the following error:

```log
/home/admin/Desktop/code/BTS/CommunityToolkit.Mvvm.SourceGenerators/CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator/WD_BTS.ViewModels.MainWindowViewModel.g.cs(63,46): error CS8716: There is no target type for the default literal.
/home/admin/Desktop/code/BTS/CommunityToolkit.Mvvm.SourceGenerators/CommunityToolkit.Mvvm.SourceGenerators.ObservablePropertyGenerator/WD_BTS.ViewModels.MainWindowViewModel.g.cs(67,45): error CS8716: There is no target type for the default literal.
```

### Regression

8.2.2

### Steps to reproduce

```text
1. Make sure you are in a Linux environment.
2. Create a new cross-platform project using Avalonia. Make sure to select the Community Toolkit for MVVM during the setup.
3. Create a new View and ViewModel.
4. In the ViewModel, try to write the following code:
[ObservableProperty]
private dynamic _selectedDevice = null!
```

### Expected behavior

Code work fine :)

### Screenshots

_No response_

### IDE and version

Rider

### IDE version

_No response_

### Nuget packages

- [ ] CommunityToolkit.Common
- [ ] CommunityToolkit.Diagnostics
- [ ] CommunityToolkit.HighPerformance
- [X] CommunityToolkit.Mvvm (aka MVVM Toolkit)

### Nuget package version(s)

8.2.2

### Additional context

_No response_

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