fixed some type errors

src/routes/api/upload/+server.ts

@@ -1,5 +1,5 @@
+import type { RequestHandler } from "@sveltejs/kit";
 
-/** @type {import('./$types').RequestHandler} */
-export async function GET(params) {
+export async function GET(params: RequestHandler) {
 	console.log('GET', params);
 }