refactor: Specify type for active array in upload process

src/app/page.tsx

@@ -154,7 +154,7 @@ export default function Home() {
     };
 
     const queue = [...chunks];
-    const active = [];
+    const active: Promise<void>[] = [];
     while (queue.length > 0 || active.length > 0) {
         while (active.length < PARALLEL_UPLOADS && queue.length > 0) {
             const task = queue.shift()!;