Add codecov token to resolve failure

[olivroy]

See r-lib/actions#834 for info

This requires admin right to fix.

[billdenney]

@sfirke, that will require your management.

[sfirke]

I just added a value for CODECOV_TOKEN as a repo secret. I don't see the failure, I'm probably not looking in the right place - did that resolve it?

[olivroy]

@sfirke I am referring to https://github.com/sfirke/janitor/actions/runs/9194907436/job/25289461527! So next time a commit is merged to main, it should pass with your change!

Thanks

Confirmed that it worked!