chore: Fix build

[jeremytchang]

This is the error we're getting in build:

ERROR in ./node_modules/vega-label/build/vega-label.module.js 557:33
Module parse failed: Unexpected token (557:33)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
|       return false;
|     }
>     let textWidth = d.textWidth ?? 0,
|       dx,
|       dy,
 @ ./node_modules/vega/build/vega.module.js 11:0-36 33:48-53
 @ ./node_modules/vega-embed/build/vega-embed.module.js
 @ ./src/histogram.js

It looks suspiciously like this one: vega/vega#3683
I added babel-loader babel core and preset-env and updated the webpack config to use babel with the hopefully the right preset and plugin, but it still doesn't fix it.

[yesudeep]

@andres-rubio-go can you please take a look at this PR, test, update, and merge the fix?