`ClassVar` shouldn't need explicit annotation

```py
class A:
a: ClassVar = 1
reveal_type(A.a) # Expression has type "Any (from omitted generics)"
```

Start by reproducing the provided ClassVar example with basedmypy and inspect the type-checking path responsible for omitted ClassVar generics. The work is done when reveal_type(A.a) reports the intended class-variable type instead of Any; the issue names no source file or test to run.

Written by the indexing model from the issue text.