test: fix flaky test-watch-mode
Fixes: https://github.com/nodejs/node/issues/44898
stress tests: https://ci.nodejs.org/view/Stress/job/node-stress-single-test/402/
also, ran python tools/test.py -J --repeat=500 test/sequential/test-watch-mode
locally (macos m1 & windows vm with arm) with no failures