Fix global declaration of staticRoot and webRoot

These variables were intended to be globals declare in the global
namespace. That this ends up on the window object is an implementation
detail of JavaScript. Remove the window. prefix put in front of
staticRoot and webRoot and include the global declaration in the
TypeScript module.

packages/web_ui/src/components/ModPackViewPage.tsx

@@ -623,7 +623,7 @@ function useExportedAsset(modPack: lib.ModPack, asset: "settings"|"locale"): Map
 				return;
 			}
 
-			let response = await fetch(`${window.staticRoot}static/${assetFilename}`);
+			let response = await fetch(`${staticRoot}static/${assetFilename}`);
 			if (response.ok) {
 				let data = await response.json();
 				setAssetData(asset === "locale" ? new Map(data) : data);