Add script to print GitHub workflow run errors

This script allows users to specify a workflow name and branch to find
the latest run. It then identifies any failed jobs within that run and
prints the last N lines of logs for each failed step.

Key features:
- Fetches the most recent workflow run for a given workflow and branch.
- Identifies jobs within the run that have a 'failure' conclusion.
- For each failed job, attempts to identify failed steps and extracts their logs.
- Prints the last 500 lines (configurable) of the log for each failed step.
- Handles various scenarios including successful runs, running workflows,
  and missing data.
- Supports GitHub token via CLI arg, env var, or ~/.github_token.
- Auto-detects repository from git remote, or accepts via CLI args.

Author: google-labs-jules[bot]