test: fix flaky child-process-exec-kill-throws
Kill the child process with SIGKILL
to make sure the child process
does not remain alive.
Fixes: https://github.com/nodejs/node/issues/20139
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines