Installation incorrectly picks the first file in an artifact folder

[jackTabsCode]

When Foreman installs an artifact that is a ZIP file, it picks the first file in the folder, which doesn't always work if your release contains other files like a license or a readme.

https://github.com/Roblox/foreman/blob/main/src/tool_cache.rs#L156

My tool Asphalt is failing to install with Foreman because it's installing the license rather than the executable named asphalt.