fix: handle leftovers recursively async (#1743)

Author: ardatan

.changeset/tidy-moles-pretend.md

@@ -0,0 +1,6 @@
+---
+'@graphql-tools/delegate': patch
+---
+
+Handle leftovers recursively but in async
+Fixes `requires-circular` test suite's second case on federation audit repository

packages/delegate/src/defaultMergedResolver.ts

@@ -101,7 +101,9 @@ export function defaultMergedResolver(
       } else {
         // not all fields are present, we need to resolve more leftovers
         // this can occur when there are circular @requires, see requires-circular audit test
-        handleLeftOver(parent, context, info, leftOver);
+        setTimeout(() => {
+          handleLeftOver(parent, context, info, leftOver);
+        }, 0);
       }
       return deferred.promise;
     }