add missing return type option when requesting bedrock uuid

src/util/minecraft.ts

@@ -14,7 +14,7 @@ export async function getJavaUuid(username: string) {
 }
 
 // https://github.com/carlop3333/XUIDGrabber/blob/main/grabber.js
-export async function getBedrockUuid(username: string): Promise<string> {
+export async function getBedrockUuid(username: string): Promise<string | null> {
   const initialPageResponse = await fetch('https://cxkes.me/xbox/xuid');
   const initialPageContent = await initialPageResponse.text();
   const token = /name="_token"\svalue="(?<token>\w+)"/.exec(initialPageContent)?.groups?.token;