Use awalsh128/cache-apt-pkgs-action on Linux

[banesullivan]

When apt-installing dependencies, we should use awalsh128/cache-apt-pkgs-action to cache these:

setup-headless-display-action/action.yml

Line 13 in a90d08f

run: sudo apt-get update && sudo apt-get install libgl1-mesa-glx xvfb -y