[debugger] Remove assert when the DebuggerTypeProxy cannot be instantiated (#34966)

[debugger] Remove assert when the DebuggerTypeProxy cannot be instantiated (#34966)

Remove the assert because we don't need to stop the debug if we cannot create the object when calling the constructor using invoke_method, if it's a DebuggerTypeProxy, we are not able to show the value of the DebuggerTypeProxy, but we still can show the Raw View, if it's not the case of DebuggerTypeProxy, we just cannot evaluate this expression, but we can continue the debug session.

Fix mono/mono#19492

Co-authored-by: thaystg <thaystg@users.noreply.github.com>