JavaScript: Avoid unhelpful magic.

The constraint `exists(callback.getParameter(i))` was getting pushed into `higherOrderCall`, which isn't a bad thing to do. However, this then led to a join on `i`, which is a very bad thing to do.

javascript/ql/src/semmle/javascript/dataflow/Configuration.qll

@@ -838,6 +838,7 @@ private predicate summarizedHigherOrderCall(
  * - The flow label mapping of the summary corresponds to the transformation from `arg` to the
  *   invocation of the callback.
  */
+pragma[nomagic]
 private predicate higherOrderCall(
   DataFlow::Node arg, DataFlow::SourceNode callback, int i, DataFlow::Configuration cfg,
   PathSummary summary