don't use Proof Using in a few files that get too many unnecessary annotations from this

theories/algebra/cofe_solver.v

 From iris.algebra Require Export ofe.
-Set Default Proof Using "Type*".
+(* FIXME: This file needs a 'Proof Using' hint, but the default we use
+   everywhere makes for lots of extra ssumptions. *)
 
 Record solution (F : cFunctor) := Solution {
   solution_car :> ofeT;

theories/algebra/sts.v

 From iris.prelude Require Export set.
 From iris.algebra Require Export cmra.
 From iris.algebra Require Import dra.
-Set Default Proof Using "Type*".
+(* FIXME: This file needs a 'Proof Using' hint, but the default we use
+   everywhere makes for lots of extra ssumptions. *)
 Local Arguments valid _ _ !_ /.
 Local Arguments op _ _ !_ !_ /.
 Local Arguments core _ _ !_ /.