Refactor test execution to use lage task runner (#5964)

packages/api/vitest.config.ts

@@ -5,5 +5,11 @@ export default {
       // print only console.error
       return type === 'stderr';
     },
+    poolOptions: {
+      threads: {
+        maxThreads: 2,
+        minThreads: 1,
+      },
+    },
   },
 };