[FEAT]: Support has_pull_requests and pull_request_creation_policy on github_repository #3472

Describe the need

Please add two attributes to the github_repository resource (and the matching data source):

• has_pull_requests (bool, default true): toggles the repository's Pull requests feature on/off, mirroring the existing has_issues / has_wiki / has_projects / has_discussions attributes
• pull_request_creation_policy (string, all | collaborators_only): the "Creation allowed by" setting that controls who may open PRs.

Both already exist on the repository object returned by the REST API (PATCH /repos/{owner}/{repo} accepts has_pull_requests and persists it); there is currently no way to manage them through the provider.

Note: this is blocked by google/go-github#4268

GitHub Installation Type

• GitHub.com (Free, Pro, or Team)
• GitHub Enterprise Server (on-premises)
• GitHub Enterprise Cloud with Personal Accounts (github.com)
• GitHub Enterprise Cloud with Managed Users/EMU (github.com)
• GitHub Enterprise Cloud with Data Residency (*.ghe.com)
• I don't know

Relevant log output

$ curl -s -H "Authorization: Bearer $TOKEN" -H "Accept: application/vnd.github+json"
    https://api.github.com/repos/OWNER/REPO | jq '{has_pull_requests, pull_request_creation_policy}'
{
  "has_pull_requests": true,
  "pull_request_creation_policy": "all"
}

$ curl -s -o /dev/null -w '%{http_code}\n' -X PATCH
    -H "Authorization: Bearer $TOKEN" -H "Accept: application/vnd.github+json"
    https://api.github.com/repos/OWNER/REPO -d '{"has_pull_requests": false}'
200

$ curl -s -H "Authorization: Bearer $TOKEN" -H "Accept: application/vnd.github+json"
    https://api.github.com/repos/OWNER/REPO | jq '{has_pull_requests, pull_request_creation_policy}'
{
  "has_pull_requests": false,
  "pull_request_creation_policy": "all"
}

Code of Conduct

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