Add pool: "forks" to vitest config of codegen

Author: aryaemami59

packages/rtk-query-codegen-openapi/vitest.config.mts

@@ -8,6 +8,7 @@ const __dirname = path.dirname(__filename);
 
 export default defineConfig({
   test: {
+    pool: "forks",
     globals: true,
     setupFiles: ['./test/vitest.setup.ts'],
     alias: {