.NET 5->6 localization regression: Static binding throws during parse

* .NET Core Version: 6.0
* Windows version: 19044.1645
* Does the bug reproduce also in WPF for .NET Framework 4.8?: N/A
* Is this bug related specifically to tooling in Visual Studio (e.g. XAML Designer, Code editing, etc...)? No
* Security issues and bugs should be reported privately, learn more via our [responsible disclosure guidelines](https://github.com/dotnet/wpf/blob/main/README.md#reporting-security-issues-and-security-bugs).

**Problem description:**

Binding to a static property that isn't the exact type will throw an exception if the current culture is invariant.

**Actual behavior:**

It might throw with [this string](https://github.com/dotnet/wpf/search?q=XmlLangGetSpecificCulture) from [this method](https://github.com/dotnet/wpf/blob/89d172db0b7a192de720c6cfba5e28a1e7d46123/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Markup/XmlLanguage.cs#L242) but I'm not sure.

**Expected behavior:**

For example: `int` should be able to bind to `TextBox.Text` without throwing an exception if `InvariantGlobalization` is enabled.

**Minimal repro:**

dotnet new wpf -o repro

Edit `MainWindow.xaml.cs`:

```cs
using System.Windows;

namespace repro
{
///
/// Interaction logic for MainWindow.xaml
///
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
public static string IWillNotCauseException { get; set; }
public static int IWillCauseException { get; set; }
}
}
```

and `MainWindow.xaml` :

```xaml

```

1. Run to confirm it works ✔
2. Go into the `.csproj` and add `true`
3. Run again and it will throw ❌
4. Go back into the project file and change `net6.0-windows` to `net5.0-windows`
5. Run again and it will work ✔

Removing static modifier:
```cs
public string IWillNotCauseException { get; set; }
public int IWillCauseException { get; set; }
```
```xaml

```
Will make it work again without exceptions.