`attrs.query()` doesn't support non-literal target expressions

If I write this on the command line:

```
buck2 query set(root//foo/...)
```

it will list all targets defined in a BUCK file within the directory `foo` or in any directory beneath it.

However, when using an `attrs.query()` argument to a rule, it seems this is not possible. buck2 errors and tells me that it expected a target literal, not a pattern. This is easiest to see when using the `deps_query` argument a standard prelude rule, but it happens with any `attrs.query()` argument. It don't really understand Rust well, but it seems like it could be because of [this](https://github.com/facebook/buck2/blob/4b9193383109aa3c466d518585d2ad737164d798/app/buck2_interpreter_for_build/src/attrs/coerce/attr_type/query.rs#L53) (and also the comment suggests it's maybe intentional?).

Can anyone shed some light on this?