test: improve debugging information for http2 test

In test-http2-session-timeout, provide the number of requests that
occurred when the test fails.

Backport-PR-URL: #22850
PR-URL: #23058
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

test/sequential/test-http2-session-timeout.js

@@ -3,11 +3,15 @@
 const common = require('../common');
 if (!common.hasCrypto)
   common.skip('missing crypto');
+const assert = require('assert');
 const http2 = require('http2');
 
 const serverTimeout = common.platformTimeout(200);
-const mustNotCall = common.mustNotCall();
 
+let requests = 0;
+const mustNotCall = () => {
+  assert.fail(`Timeout after ${requests} request(s)`);
+};
 const server = http2.createServer();
 server.timeout = serverTimeout;
 
@@ -32,6 +36,8 @@ server.listen(0, common.mustCall(() => {
     request.resume();
     request.end();
 
+    requests += 1;
+
     request.on('end', () => {
       const diff = process.hrtime(startTime);
       const milliseconds = (diff[0] * 1e3 + diff[1] / 1e6);