Test coverage issue with Storybook 8.3.4

[tol-is]

Summary

I'm having an issue with the --coverage flag, which fails with:

[Test runner] An error occurred when evaluating code coverage:
storybook:test: [Test]       The code in this story is not instrumented, which means the coverage setup is likely not correct.
storybook:test: [Test]       More info: https://github.com/storybookjs/test-runner#setting-up-code-coverage

What's strange is that the issue happens, whether i'm running tests on a build (prod or test), and on dev mode. Without the --coverage flag the tests are running successfully. I looked into the docs several times, but haven't found any leads, and i'm completely out of ideas.

Any help would be appreciated!

Additional information

No response

Create a reproduction

1. https://github.com/tol-is/storybook-coverage-issue-repro

2. Also created a non-monorepo setup, and had the exactly same issue
   https://github.com/tol-is/storybook-coverage-solo-repro

3. And last, created a nextjs setup, and added testing as it was out-of-the-box, and still getting the same not instrumented error
   https://github.com/tol-is/storybook-next-coverage-repro

[valentinpalkovic]

cc @yannbf