Update GitHub token permission to remove unused ones

[fharper]

Which version of kubefirst are you using?

2.4.8

Which cloud provider?

None specific

Which DNS?

None specific

Which installation type?

None specific

Which distributed Git provider?

GitHub

Did you use a fork of gitops-template?

No

Which Operating System?

None specific

What is the issue?

The GitHub token permission don't need:

• admin:org_hook as we already have the admin:repo_hook which is enough for our needs since we do not need organization level hook. This one need to be tested just to be sure.
• admin:ssh_signing_key as we don't sign the code committed by kbot. It is used internally, but it doesn't need to be needed for the user.

Once the check for those permissions are moved, we also need to update the docs at https://docs.kubefirst.io/common/gitAuth to reflect that.

Code of Conduct

• [X] I agree to follow this project's Code of Conduct