Add installation of libgl1-mesa-dev in workflow

Author: SomeGuyWhoLovesCoding

.github/workflows/main.yml

@@ -73,6 +73,7 @@ jobs:
           sudo apt install libx11-dev
           sudo apt install libxrandr-dev
           sudo apt-get install libxinerama-dev
+          sudo apt-get install libgl1-mesa-dev
           haxelib install format --quiet
           haxelib install hxp --quiet
           haxelib install hxcpp > /dev/null --quiet