Function resolve_github_slug_in 

pub fn resolve_github_slug_in(
    override_owner: Option<&str>,
    override_name: Option<&str>,
    cwd: &Path,
) -> Result<RepoSlug>

Resolve the GitHub repository identity for the repo at cwd.

Precedence: a non-empty (override_owner, override_name) config override wins; otherwise the origin remote is parsed once (github.com URLs only).