Apply changes from PathOfBuildingCommunity/PathOfBuilding-PoE2#1789 (#9818)

Co-authored-by: YangLeoZhao <YangLeoZhao@users.noreply.github.com>

Author: github-actions[bot]

src/HeadlessWrapper.lua

@@ -51,6 +51,9 @@ end
 function GetScreenScale()
 	return 1
 end
+function GetVirtualScreenSize()
+	return GetScreenSize()
+end
 function GetDPIScaleOverridePercent()
 	return 1
 end