Fix dynamic imports issue in core-frontend's vitest v8 coverage run

[hl662]

After #7340 and #7710, vitest's browser API is not playing nicely with their v8 coverage reporter, it's having issues with importing:

TypeError: Failed to fetch dynamically imported module: http://localhost:63315/@id/@vitest/coverage-v8/browser?import

One guess I have is Vite's build output is not creating the right filename for the compiled coverage-v8/browser.

In the meantime, we had to disable coverage reporting for core-frontend (other non-browser packages using vitest are fine).