test_runner: improve describe.only behavior
Supersedes https://github.com/nodejs/node/pull/48932
this fixes two major issues with describe
that will now run regardless of it not being marked with only
:
- if a test is marked with only, it is not needed to mark all of its ancestors with
only
- if a suite is marked as
only
, and no nested test is marked withonly
, all its decendents will run
this aligns the behavior with other test runners I have compared with