[FEATURE]: Support test runners that support per-test concurrency #7510
Description
Package Name
node:test
Package Version(s)
No response
Describe the feature you'd like
Support features of test runners that run individual tests concurrently, not just test files.
Is your feature request related to a problem?
I've been experimenting with node:test (we currently use mocha), and have found we would gain significant performance gains by using concurrency: true to run individual tests within a file in parallel, not just files. However, node:test is not supported by dd-trace, so that's currently a non-starter. I don't think the Manual Testing API would be able to handle concurrency: true either, see #5378 (comment).
Describe alternatives you've considered
According to the documentation, Jest's equivalent feature test.concurrent is not supported.
Mocha does not have this feature AFAICT.
The docs do not mention whether the Vitest support includes Vitest's test.concurrent, could it be clarified whether that is supported? If so that's a potential option, but tbh it would be nice to use node's built-in runner (vitest is overkill for our needs).
Additional context
No response