API response says the force pushing is allowed when it is not allowed

Summary

• When force pushing is prevented by prevent_pushing_and_force_pushing, the UI correctly shows that no one is allowed to force push, but the API response says they are allowed to force push

Full context: #435500 (comment 1702617086)

Steps to reproduce

1. Create a protected branch
2. Create a security policy with prevent_pushing_and_force_pushing: true for the protected branch
3. View the protected branch in the UI
4. View the protected branch information from the API

Example Project

What is the current bug behavior?

UI says No one is allowed to force push; API says force pushing is allowed

What is the expected correct behavior?

UI says No one is allowed to force push; API says force pushing is not allowed

Relevant logs and/or screenshots

See them at #435500 (comment 1702617086)

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes

• backend