CI: Set permissions for GitHub actions (#1336)
CI: Set permissions for GitHub actions (#1336)

Restrict the GitHub token permissions only to the required ones.
Even if the attackers will succeed in compromising workflow, they won’t be able to do much.

Ref. https://docs.github.com/en/actions/using-jobs/assigning-permissions-to-jobs
rmagick/rmagick,rmagick/rmagick,rmagick/rmagick