fix(health): open handle when using pingCheck in jest environment

resolves #1466

lib/utils/promise-timeout.ts

@@ -16,18 +16,19 @@ export class TimeoutError extends Error {}
  *
  * @internal
  */
-export const promiseTimeout = function(
+export const promiseTimeout = function (
   ms: number,
   promise: Promise<any>,
 ): Promise<any> {
-  // Create a promise that rejects in <ms> milliseconds
-  let timeout = new Promise((_, reject) => {
-    let id = setTimeout(() => {
-      clearTimeout(id);
-      reject(new TimeoutError('Timed out in ' + ms + 'ms.'));
-    }, ms);
-  });
-
-  // Returns a race between our timeout and the passed in promise
-  return Promise.race([promise, timeout]);
+  let timer: NodeJS.Timeout;
+  return Promise.race([
+    promise,
+    new Promise(
+      (_, reject) =>
+        (timer = setTimeout(
+          () => reject(new TimeoutError(`Timed out in ${ms}ms.`)),
+          ms,
+        )),
+    ),
+  ]).finally(() => clearTimeout(timer));
 };