If a WPF dialog is loaded in a background thread, and disposable components are not manually disposed, app crashes

### Description

This issue appears to be a regression in .net 8 WPF. I've linked a minimal repro project that duplicates the issue we're seeing. App does the following:
- Main window loads
- Button on main window launches a dialog in a background thread
- Dialog has a webview2 control

Closing the dialog without manually disposing the webview2 crashes the application. If you click the "close me" button I added to the dialog, it disposes the webview2, and the crash doesn't happen.

Switching the runtime from .net 8 to .net 7 fixes the issue. You can close without disposing the controls.

### Reproduction Steps

Minimal repro project showing the issue:
[WPFDialogTest.zip](https://github.com/dotnet/wpf/files/14605395/WPFDialogTest.zip)

### Expected behavior

App should not throw an exception that terminates in an Environment.FailFast

### Actual behavior

App throws an exception if WebView2 is not manually disposed:

System.ExecutionEngineException
HResult=0x80131506
Message=Exception of type 'System.ExecutionEngineException' was thrown.

An unhandled exception of type 'System.ExecutionEngineException' occurred in System.Private.CoreLib.dl

### Regression?

Yes, working in .net 6 and .net 7

### Known Workarounds

Manually disposing webview2 fixes issue.

### Impact

Crash is reproducible in prod, and was blocking upgrade from .net 6 to .net 8 until we found the workaround.

### Configuration

.net 8.0.202, win11 22635.3286, x64

### Other information

_No response_