Restrict permissions for GITHUB_TOKEN in our workflows

Restrict permissions for GITHUB_TOKEN in our workflows

Added using https://github.com/step-security/secure-workflows
For more information see:
- https://github.com/ossf/scorecard/blob/d8fefc9b246db3600c777e9d60d441d7c386ce1d/docs/checks.md#token-permissions
- https://github.blog/changelog/2021-04-20-github-actions-control-permissions-for-github_token/