Adapt to rocq-prover/rocq#21767 (qglobal is not qvar) (#214)

<!-- This is an auto-generated description by cubic. -->
## Summary by cubic
Adapts Hammer to the latest `rocq` sort API from rocq-prover/rocq#21767
by replacing `QSort` with `GSort` and `VSort`; both map to `$Type` to
preserve behavior.

<sup>Written for commit 06fa3d2.
Summary will update on new commits.</sup>

<!-- End of auto-generated description by cubic. -->

Author: SkySkimmer

src/plugin/hammer_main.ml

@@ -35,7 +35,7 @@ let hhterm_of_sort s = match s with
   | Prop -> mk_id "$Prop"
   | Set  -> mk_id "$Set"
   | Type _ -> mk_id "$Type"
-  | QSort _ -> mk_id "$Type"
+  | GSort _ | VSort _ -> mk_id "$Type"
 
 let hhterm_of_constant c =
   tuple [mk_id "$Const"; hhterm_of_global (Names.GlobRef.ConstRef c)]