Warning for new GH feature in beta

Hi folks, just creating this issue as a warning for an upcoming feature from GitHub

https://docs.github.com/en/organizations/managing-peoples-access-to-your-organization-with-roles/managing-security-managers-in-your-organization

Setting a team as a security manager (as on org-wide setting, so out of "scope" of safe-settings app) causes the relevant team to be added to every repository in the organization. This causes safe-settings team differ to always identify out-of-sync teams for every repo, causing re-sync for every repo as well. Further, the attempted sync will fail with:

```
error calling find for Teams HttpError: You cannot remove repositories from a security manager team. for repo:
```

I think adding this team to global teams in settings.yaml will mitigate this (though I will need to check tomorrow), but there is no clear way to keep these settings and security managers in sync as of now