Revert "chore: update to electron 9-x-y (#102011)" (#103599)

This reverts commit 3d0d50caf8.

test/unit/electron/index.js

@@ -12,10 +12,6 @@ const events = require('events');
 // const MochaJUnitReporter = require('mocha-junit-reporter');
 const url = require('url');
 
-// Disable render process reuse, we still have
-// non-context aware native modules in the renderer.
-app.allowRendererProcessReuse = false;
-
 const defaultReporterName = process.platform === 'win32' ? 'list' : 'spec';
 
 const optimist = require('optimist')
@@ -121,7 +117,6 @@ app.on('ready', () => {
 			nodeIntegration: true,
 			enableWebSQL: false,
 			enableRemoteModule: false,
-			spellcheck: false,
 			nativeWindowOpen: true,
 			webviewTag: true
 		}