Various GitHub Action xcat_test fixes

Upgrade to actions/checkout@v4 to fix the following GitHub warning:

Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions/checkout@v3. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.
Add a 60 minute timeout. Let's not waste resources if our CI job has issues
Remove duplicate makedhcp_n_linux test case
Add step names

xcat2 / xcat-core