Skip API reference generation for non-Python projects

[jeroenjanssens]

Problem

Running great-docs build in a Go-only project (project_type: go) blocks on an interactive prompt:

Could not auto-detect package name. Enter package name for API reference (or press Enter to skip):

_add_api_reference_config() ran for every project regardless of type. For a Go project there is no root pyproject.toml or top-level Python package, so _detect_package_name() returns None and the build drops into an input() prompt — which hangs non-interactive and uvx-driven builds.

Fix

Gate the API-reference step on the existing Config.is_python_project, so non-Python projects skip it cleanly. This mirrors how the PyPI link already defaults off for non-Python projects, and needs no new config key — project_type already carries the necessary information. The separate Go CLI reference path is unaffected.

if not self._config.is_python_project:
    print("API reference skipped (non-Python project)")
    self._has_api_reference = False
    return

Testing

• Added test_add_api_reference_config_non_python_project, which patches builtins.input to fail loudly if the prompt is ever reached for a Go project.
• All 8 add_api_reference_config tests pass.
• Verified end-to-end: great-docs build on a Go project (velocirepo) now completes without prompting, prints API reference skipped (non-Python project), and still generates the Go CLI reference.

The 23 pre-existing failures in tests/test_synthetic.py are unrelated to this change (confirmed by reproducing them on main).

[has2k1]

LGTM