Resolve the CLI and helper programs via a safe PATH lookup (never the working directory) - #1188

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-python@v5, codecov/codecov-action@b9fd7d16f6d7d1b5d2bec1a2887e65ceed900238. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/