Wildcard rules shouldn't be allowed

If you write a rule like this it's going to bind to *every AST node in every file* before doing further filtering. This is, of course, pathologically expensive.

```
`$foo` where {
...
}
```

Example here: https://github.com/biomejs/biome/issues/6210

There's no real use case for such a rule so we should disallow it.
