[mono] Don't save byref `System.Void` into `MonoDomain::typeof_void`. (#40405)

[mono] Don't save byref `System.Void` into `MonoDomain::typeof_void`. (#40405)

`mono_type_get_object_checked` will return the `MonoReflectionType`
referred to by `MonoDomain::typeof_void` if present. If a byref
`System.Void` is stored in this field, then
`get_ContainsGenericParameters` applied to `System.Void` will loop
indefinitely, because our implementation of
`get_ContainsGenericParameters` expects `GetElementType` to yield a
`MonoReflectionType` with one layer of "type function application"
removed.

Fixes https://github.com/dotnet/runtime/issues/37489.