test: fix flaky test-vm-timeout-rethrow

The intention of test case is to make sure that `timeout` property is honored
and the code in context terminates and throws correct exception. However in
test case, the code inside context would complete before `timeout` for windows
and would sometimes fail. Updated the code so it guarantee to not complete
execution until timeout is triggered.

Fixes: https://github.com/nodejs/node/issues/11261
PR-URL: https://github.com/nodejs/node/pull/11530


Reviewed-By: James M Snell <jasnell.gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Josh Gavant <josh.gavant@outlook.com>