download: Get latest build from last match instead of sorting

This fails for 12L: SP2A.220305.013.A3 < SQ1D.220205.004. Google always
adds builds to the bottom anyway, so just pick the last matched URL.

src/images/download.ts

@@ -64,7 +64,7 @@ async function getUrl(type: ImageType, buildId: string, device: string, cache: I
   }
 
   if (buildId == 'latest') {
-    return matches.map(m => m[1]).sort((a, b) => b.localeCompare(a))[0]
+    return matches[matches.length - 1][1]
   }
   return matches[0][1]
 }