Runner cannot be updated via runnerUpdate mutation by non-admins

Description

I tested running a runner update on production with a maintainer account and got the following result:

Steps to reproduce

1. Enable project_runner_edit_form_vue
2. Login as maintainer of a project with runners (non-admin user)
3. Visit CI/CD settings -> Runners
4. Select a Runner's edit button (pencil icon)
5. Save the form

Expected: The form should save the changes

Result: The runner cannot be saved and an error appears.