Set permissions for Github Workflows

[joycebrum]

Hi, I work at Google together with the OpenSSF to help open source projects improve their supply chain security by using the OpenSSF Scorecard as a guide.

I would like to suggest a PR to change the top-level and run-level permissions for GitHub workflows to only grant write permissions at the run level.

This is necessary because, by default, GitHub grants write-all permissions to all workflows, which could be exploited by an attacker if a workflow is compromised. Limiting permissions is a simple and effective way to limit the impact of a compromised workflow.

Therefore, both the OpenSSF Scorecard and GitHub recommend using minimally scoped credentials.

Please let me know if you have any questions or concerns.

[joycebrum]

If a PR is welcome let me know and I'll submit it ASAP

[diogoteles08]

Hi! I'm Diogo and I work along with Joyce in Google’s Open Source Security Team.

This issue has been idle for a while. Do you plan on considering this suggestion? Since the changes are actually very simple, I'll take the liberty to raise a PR with them and possibly ease your evaluation =)

Thanks!