test: refactor test-*-ci-reneg-attack.js

[Trott]

Refactor test-tls-ci-reneg-attack:

• Use port 0 (OS-assigned available port) rather than common.PORT
• Remove unnecessary boolean that causes race condition failure on some
  operating systems

Refactor that test and test-https-ci-reneg-attack:

• Check all stderr, not just the chunk coming in now, in case it breaks
  up chunks in the middle of where the regexps are supposed to match.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

[nodejs-github-bot]

@Trott build started: https://ci.nodejs.org/blue/organizations/jenkins/node-test-pull-request-lite-pipeline/detail/node-test-pull-request-lite-pipeline/2355/pipeline

[Trott]

Pummel tests are not run in CI, so lite CI should be sufficient. Might run a full pummel test suite if we get the pummel tests fixed (in other PRs)...

[Trott]

Closing in favor of #25700 and #25720. (Those both need reviews, so feel free to head over there to get them landed and get the pummel test suite green again.)