cli: Add missing nyc dep when creating JS packages

[anomiex]

Changes proposed in this Pull Request:

When creating a JS package, the CLI is pre-filling the test-coverage
script with a call to nyc. But it wasn't also pre-adding a dependency
on nyc, resulting in coverage not working for several packages.

Also, add the missing dep to those packages.

Jetpack product discussion

None

Does this pull request change what data or activity we track or use?

No

Testing instructions:

• Check that the coverage job isn't failing to run for these packages (e.g. not this).
  • ✔️ https://github.com/Automattic/jetpack/runs/4926248885?check_suite_focus=true#step:9:505
  • ✔️ https://github.com/Automattic/jetpack/runs/4926248885?check_suite_focus=true#step:9:1126
  • ✔️ https://github.com/Automattic/jetpack/runs/4926248885?check_suite_focus=true#step:9:1212
  • ✔️ https://github.com/Automattic/jetpack/runs/4926248885?check_suite_focus=true#step:9:1320

[matticbot]

Caution: This PR has changes that must be merged to WordPress.com
Hello anomiex! These changes need to be synced to WordPress.com - If you 're an a11n, please commandeer and confirm D73664-code works as expected before merging this PR. Once this PR is merged, please commit the changes to WP.com. Thank you!
This revision will be updated with each commit to this PR

[anomiex]

I spotted this while looking into why the coverage job has started hitting its time limit. This'll probably actually make that problem slightly worse, but it needs to be fixed.

[github-actions]

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[github-actions]

Great news! One last step: head over to your WordPress.com diff, D73664-code, and commit it.
Once you've done so, come back to this PR and add a comment with your changeset ID.

Thank you!

[anomiex]

r238858-wpcom