Investigate flaky test-https-server-keep-alive-timeout

[Trott]

• Version: v8.0.0-pre
• Platform: aix61
• Subsystem: test, https

https://ci.nodejs.org/job/node-test-commit-aix/6219/nodes=aix61-ppc64/console

not ok 675 parallel/test-https-server-keep-alive-timeout
  ---
  duration_ms: 1.803
  severity: fail
  stack: |-
    events.js:182
          throw er; // Unhandled 'error' event
          ^
    
    Error: read ECONNRESET
        at exports._errnoException (util.js:1026:11)
        at TLSWrap.onread (net.js:607:25)
  ...

[Trott]

1 second timer etc., test seems race-prone.

[Trott]

Easily replicated with tools/test.py -j 64 --repeat 128 test/parallel/test-https-server-keep-alive-timeout.js

Easiest solution is to move test to sequential but a refactor may help keep it in parallel.

[Trott]

Removing AIX from description as it's not AIX-specific.

[Trott]

Mitigation: #13312

[Trott]

Fail again in https://ci.nodejs.org/job/node-test-commit-aix/6249/nodes=aix61-ppc64/console.