test: mark child-process-exec-kill-throws flaky
Refs: https://github.com/nodejs/node/issues/12053 Refs: https://github.com/nodejs/node/pull/11038
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
commit message follows [commit guidelines][]
Affected core subsystem(s)
test
cc/ @cjihrig @nodejs/testing @nodejs/platform-windows