GH binary discovery

[johngeorgewright]

This fixes a couple of problems I noticed when trying to use this action.

1. The warnings of Node.js version.
   • Support for Node v20 is being dropped soon, so I upgrade to v24
   • Also upgraded other dependencies and actions while I was at it
2. The path of the gh binary has changed in cli/cli
   • To future proof this from happening again I've added a method to find the gh binary in the extracted download
   • My caches are already broken, so the search is done post cache discovery for this scenario.