test: refactor test-gc-http-client-timeout

Due to server response delay, all possible requests are created anyway.
Instead of doing `36 * os.availableParallelism()` requests, use a fixed
number.

Refs: nodejs#48078 (comment)
PR-URL: nodejs#48292
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>

test/sequential/test-gc-http-client-timeout.js

@@ -1,12 +1,10 @@
 'use strict';
 // Flags: --expose-gc
-// just like test-gc-http-client.js,
-// but with a timeout set
+// Like test-gc-http-client.js, but with a timeout set.
 
 const common = require('../common');
 const onGC = require('../common/ongc');
 const http = require('http');
-const os = require('os');
 
 function serverHandler(req, res) {
   setTimeout(function() {
@@ -16,20 +14,16 @@ function serverHandler(req, res) {
   }, 100);
 }
 
-const cpus = os.availableParallelism();
-const numRequests = 36;
-let createClients = true;
+const numRequests = 128;
 let done = 0;
-let count = 0;
 let countGC = 0;
 
 const server = http.createServer(serverHandler);
-server.listen(0, common.mustCall(() => getAll(numRequests)));
+server.listen(0, common.mustCall(() => {
+  getAll(numRequests);
+}));
 
 function getAll(requestsRemaining) {
-  if (!createClients)
-    return;
-
   if (requestsRemaining <= 0)
     return;
 
@@ -41,15 +35,11 @@ function getAll(requestsRemaining) {
 
   req.setTimeout(10, common.mustCall());
 
-  count++;
   onGC(req, { ongc });
 
   setImmediate(getAll, requestsRemaining - 1);
 }
 
-for (let i = 0; i < cpus; i++)
-  getAll(numRequests);
-
 function cb(res) {
   res.resume();
   done += 1;
@@ -63,10 +53,9 @@ setImmediate(status);
 
 function status() {
   if (done > 0) {
-    createClients = false;
     global.gc();
-    console.log(`done/collected/total: ${done}/${countGC}/${count}`);
-    if (countGC === count) {
+    console.log(`done/collected/total: ${done}/${countGC}/${numRequests}`);
+    if (countGC === numRequests) {
       server.close();
       return;
     }