use pair for consistency

src/xrpld/app/hook/applyHook.h

@@ -15,7 +15,7 @@
 #include <memory>
 #include <optional>
 #include <queue>
-#include <tuple>
+#include <utility>
 #include <vector>
 #include <wasmedge/wasmedge.h>
 
@@ -175,7 +175,7 @@ struct HookResult
         false;  // hook_again allows strong pre-apply to nominate
                 // additional weak post-apply execution
     std::shared_ptr<STObject const> provisionalMeta;
-    std::set<std::tuple<AccountID, uint256 /* namespace */>>
+    std::set<std::pair<AccountID, uint256 /* namespace */>>
         foreignStateGrantCache;  // add found grants here to avoid rechecking
 };