ci: fail pull requests that target master - #11

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@6f8efc29b200d32929f49075959781ed54ec270c, actions/checkout@11d5960a326750d5838078e36cf38b85af677262, actions/setup-go@7b8cf10d4e4a01d4992d18a89f4d7dc5a3e6d6f4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/