refactor: drop unused get_github_id wrapper orphaned by #932

[carlos4s]

Summary

get_github_id in gittensor/utils/github_api_tools.py:321 is a 3-line public function with no production callers. PR #932 introduced get_github_identity (which returns GitHubIdentityResult(github_id, status) so callers can distinguish transient failures from invalid auth) and migrated every production site. The wrapper has been dead code since #932 merged on 2026-05-06.

def get_github_id(token: str) -> Optional[str]:
    """Get GitHub numeric user id (as string) using a PAT."""
    return get_github_identity(token).github_id

grep -rn "get_github_id\b" gittensor/ neurons/ confirms the only match is the definition itself. The remaining references live in tests/utils/test_github_api_tools.py:31 (module-level alias) and :364-376 (test_get_github_id_retry_logic). The retry path that test exercises is already covered by the sibling test_get_github_identity_marks_5xx_as_transient / _marks_rate_limit_as_transient / _marks_bad_json_as_transient tests at :384-440, which patch requests.get at the same boundary.

This PR:

• removes the wrapper function (3 lines + surrounding blanks)
• removes the test alias and the duplicate retry test (21 lines)

Net: +0 / -26 lines, one fewer public symbol on gittensor.utils.github_api_tools.

Related Issues

Closes #1186.

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other

Testing

• uv run --extra dev pytest tests/utils/test_github_api_tools.py — all 88 tests pass.
• grep -rn "get_github_id\b" gittensor/ neurons/ tests/ docs/ scripts/ — returns no hits after the change.

Checklist

• Code follows project style guidelines
• Self-review completed
• Changes are documented (if applicable)