Investigate flaky test-tls-set-secure-context

[targos]

• Version: master
• Platform: linuxone, ubuntu1604 (shared lib)
• Subsystem: tls

The test was just added today in #23644

https://ci.nodejs.org/job/node-test-pull-request/18030/

12:55:25 not ok 2352 parallel/test-tls-set-secure-context
12:55:25   ---
12:55:25   duration_ms: 120.93
12:55:25   severity: fail
12:55:25   exitcode: -15
12:55:25   stack: |-
12:55:25     timeout
12:55:25   ...

[cjihrig]

Proposed fix in #23811. Sorry for breaking things.