fix(ci): set maxWorkers to 1 for jest tests

Author: chenba

jest.preset.js

@@ -1,3 +1,6 @@
 const nxPreset = require('@nx/jest/preset').default;
 
-module.exports = { ...nxPreset };
+module.exports = {
+  ...nxPreset,
+  maxWorkers: 1,
+};