Support for Branch Protection `bypassForcePushAllowances`

## Prerequisites:

Available via current UI:

## New Feature

Can safe-settings add support for specifying who can force push to a protected branch?
Currently we are only able to set `allow_force_pushes: true | false` for branch protection rules.

### API support
This does not appear to be supported by the [REST API](https://docs.github.com/en/rest/branches/branch-protection#update-branch-protection).

However, this is available via the [GraphQL API](https://docs.github.com/en/graphql/reference/objects#branchprotectionrule) as `bypassForcePushAllowances`