test: merge test with unnecessary child process

Test didn't require child process creation. While this test has not been
unstable, child process creation is slower and can be flaky in ci, so
test directly for the segfault regression.

PR-URL: https://github.com/nodejs/node/pull/25025


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>