(🐞) Wrong error code on bare enum literal

```py
from enum import Enum

class E(Enum):
    A = 1
    
a: E.A  # error: Invalid type: try using Literal[E.A] instead?  [misc]
b: 1   # error: Invalid type: try using Literal[1] instead?  [valid-type]
```

I'll fix this when I'm free.