[backport to v6] test: begin normalizing fixtures use
Original PR: https://github.com/nodejs/node/pull/14332
CI: https://ci.nodejs.org/job/node-test-pull-request/10789/
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
Affected core subsystem(s)
test