build: speedy tests on circle by splitting the test files into multiple jobs (#21015)

* build: let circleci divide our test suites in two

* well our tests rely on side affects, thats cool I guess

spec/api-remote-spec.js

@@ -1,19 +1,15 @@
 'use strict'
 
-const chai = require('chai')
-const dirtyChai = require('dirty-chai')
+const { expect } = require('chai')
 const path = require('path')
 const { resolveGetters } = require('./expect-helpers')
 const { ifdescribe } = require('./spec-helpers')
 
 const { remote, ipcRenderer } = require('electron')
 const { ipcMain, BrowserWindow } = remote
-const { expect } = chai
 
 const features = process.electronBinding('features')
 
-chai.use(dirtyChai)
-
 const comparePaths = (path1, path2) => {
   if (process.platform === 'win32') {
     path1 = path1.toLowerCase()