fix public inputs in zkprogram type: don't require pure

Author: mitschabaude

src/lib/proof-system/zkprogram.ts

@@ -618,8 +618,8 @@ function ZkProgram<
 
 type ZkProgram<
   Config extends {
-    publicInput?: ProvableTypePure;
-    publicOutput?: ProvableTypePure;
+    publicInput?: ProvableType;
+    publicOutput?: ProvableType;
     methods: {
       [I in string]: {
         privateInputs: Tuple<PrivateInput>;