Working until i upgraded test-runner from 0.10.0 to 0.11.0; didn't change anything else.
nyc report --reporter=lcov -t coverage/storybook --report-dir coverage/storybook
ENOENT: no such file or directory, scandir '/home/runner/work/admin/admin/coverage/storybook'
fwiw, we use next.js & we do run the test-runner with --coverage, etc