refactor: simplify process object initialization for sandboxed renderers (#14878)

Also fix `process.windowsStore`.

lib/common/init.js

@@ -50,13 +50,4 @@ if (process.platform === 'win32') {
   process.__defineGetter__('stdin', function () {
     return stdin
   })
-
-  // If we're running as a Windows Store app, __dirname will be set
-  // to C:/Program Files/WindowsApps.
-  //
-  // Nobody else get's to install there, changing the path is forbidden
-  // We can therefore say that we're running as appx
-  if (__dirname.includes('\\WindowsApps\\')) {
-    process.windowsStore = true
-  }
 }