[Tooling] Add separate caching rules for vcpkg

[sorcerer86pt]

Prerequisites

• I have searched for similar issues and confirmed this is not a duplicate

Game Version

• Command & Conquer Generals
• Command & Conquer Generals: Zero Hour
• Other (please specify below)

Bug Description

The vcpkg builds on github take a lot longer than the prior cmake only builds

Reproduction Steps

CI github with vcpk enabled takes way too much time

Additional Context

possible need to enable caching of prebuild vcpkg dependencies

[aliendroid1]

Even on my local PC ffmpeg takes a long time to compile so I suspect that is what's taking up the majority of the time