migrate CI workaround (#3534)

test/benchmark.js

@@ -94,6 +94,3 @@ urls.forEach(function(url) {
         });
     });
 });
-setInterval(function() {
-    process.stderr.write("\0");
-}, 5 * 60 * 1000).unref();

test/release/benchmark.js

@@ -1,3 +1,6 @@
+setInterval(function() {
+    process.stderr.write("\0");
+}, 8 * 60 * 1000).unref();
 require("./run")([
     "-b",
     "-b braces",