Update vitest.config.ts

Signed-off-by: Sora Morimoto <[email protected]>

Author: smorimoto

Diff for: vitest.config.ts

@@ -3,5 +3,8 @@ import { defineConfig } from "vitest/config";
 export default defineConfig({
   test: {
     testTimeout: 10000,
+    typecheck: {
+      enabled: true,
+    },
   },
 });