Rate limits cause a hard failure instead of retry

Description:

This action fails when a GitHub API rate limit is encountered, e.g., https://github.com/astral-sh/uv/actions/runs/18688106891/job/53286544594

Run actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065
Installed versions
  GraalPy version 24.1 was not found in the local cache
  Error: API rate limit exceeded for installation. If you reach out to GitHub Support for help, please include the request ID 5841:12068:2A62DF:B7984D:68F7A08C and timestamp 2025-10-21 15:02:36 UTC. For more on scraping GitHub and how it may affect your rights, please review our Terms of Service (https://docs.github.com/en/site-policy/github-terms/github-terms-of-service)

GitHub's rate limits have recently been reduced, and we're seeing far more failures from this.

While I'd generally expect setup-python to avoid hitting a rate-limited API, I'd also expect it to retry on spurious HTTP errors and handle rate limiting, especially for a first-party API.

Action version:

5.6.0

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Tools version:

Repro steps:

See description. Requires hitting a GitHub rate limit.

Expected behavior:

I expect the action to retry in a backoff, respecting the retry-after header.

Actual behavior:

The action hard fails.

Start with the linked setup-python workflow failure and trace the action's GitHub API request path for Python installation. Reproduce the rate-limit response, then verify that the action retries with backoff and respects the retry-after header instead of hard-failing.