Workers do not work in start-local

[xintongxia]

How to reproduce?

Go to examples/las, replace the LASLoader with LASWorkerLoader. And do yarn start-local.

Line 8 - 13 should like the following,

import {LASWorkerLoader} from '@loaders.gl/las';
// import {PLYWorkerLoader} from '@loaders.gl/ply';
import {load, registerLoaders} from '@loaders.gl/core';

// Additional format support can be added here, see
registerLoaders(LASWorkerLoader);