Revert "fix: unref timers implicitly scheduled for MAX_TIMEOUT"

This reverts commit d4a65aa.

Author: JoshuaKGoldberg

lib/runnable.js

@@ -234,7 +234,7 @@ Runnable.prototype.clearTimeout = function () {
  */
 Runnable.prototype.resetTimeout = function () {
   var self = this;
-  var ms = this.timeout();
+  var ms = this.timeout() || MAX_TIMEOUT;
 
   this.clearTimeout();
   this.timer = setTimeout(function () {
@@ -243,11 +243,7 @@ Runnable.prototype.resetTimeout = function () {
     }
     self.callback(self._timeoutError(ms));
     self.timedOut = true;
-  }, ms || MAX_TIMEOUT);
-
-  if (!ms) {
-    this.timer.unref();
-  }
+  }, ms);
 };
 
 /**