- Set AGENT_TOOLSDIRECTORY via step-level env on setup-python (not
GITHUB_ENV which only applies to subsequent steps)
- Use runner.temp for toolcache dir (always writable, no sudo needed)
- Remove .github/workflows/build.yml to prevent duplicate CI runs
- Remove unused Windows env check step
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>