test: use threads pool

Author: velut

vitest.config.ts

@@ -2,7 +2,7 @@ import { defineConfig } from "vitest/config";
 
 export default defineConfig({
 	test: {
-		pool: "vmThreads",
+		pool: "threads",
 		testTimeout: 60_000, // Analyzing npm packages takes time.
 		coverage: { include: ["src/**"] },
 	},