mypy crashes when passing multiple variadic tuples

```python
class A[*Ts]: ...

type x0 = tuple[int, ...]
type x1 = tuple[int, *tuple[int, ...]]

A[*x0, *x0]  # E: More than one Unpack in a type is not allowed
A[*x1, *x1]  # crash
```

https://mypy-play.net/?mypy=master&python=3.12&gist=f6165c82cda9047dbe8aa7ab5c746eda