investigate flaky sequential/test-http-server-keep-alive-timeout-slow-client-headers

[Leko]

• Version: v10.0.0-pre
• Platform: debian8-x86
• Subsystem: test

https://ci.nodejs.org/job/node-test-commit-linux/16738/nodes=debian8-x86/console

not ok 2039 sequential/test-http-server-keep-alive-timeout-slow-client-headers
  ---
  duration_ms: 0.169
  severity: fail
  stack: |-
  ...

Caused by #19018

[BridgeAR]

I am closing the reports without stack traces. I have the feeling this got resolved. If they come back, we can check again what to do.