[v18.x backport] test_runner: avoid swallowing of asynchronously thrown errors
requested to merge github/fork/fossamagna/backport-v18-test-runner-extraneous-async-fail into v18.x-staging
This RP is backport of https://github.com/nodejs/node/pull/45264 to v18.x.
Refs: https://github.com/nodejs/node/pull/45264#issuecomment-1366958584