Remove access from teams that are not specified in the config

## Problem Description

### What is actually happening
When I remove a team from the `teams` collection, said team is not removed from the repository's permissions.

### What is the expected behavior
Only the teams listed under the `teams` should have access to the repository. If the `teams` key is missing from the configuration, I would expect the permissions to be handled from the repository's settings page.

I did not experiment with `collaborators` but I would expect a similar behavior.

### Error output, if available
n/a

## Context

### Are you using the hosted instance of probot/settings or running your own?
Running my own
### If running your own instance, are you using it with github.com or GitHub Enterprise?
GHEC

#### Version of probot/settings
safe-settings:2.0.0

#### Version of GitHub Enterprise
cloud