test: fix flaky test-http-writable-true-after-close
Fixes: https://github.com/nodejs/node/issues/16321
This will need full stress test CI, coming shortly. (But it did fix it on my macOS.)
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
commit message follows commit guidelines
Affected core subsystem(s)
test