Extension settings broken under GNOME 40

[drjhe]

The extension's panel components work fine if the metadata.json is updated to include shell versions "40.beta" and "40", but the preferences dialogue does not. Instead I get a 'Something's gone wrong' box with the following error:

TypeError: w.show_all is not a function

Stack trace:
  buildPrefsWidget@/usr/share/gnome-shell/extensions/freon@UshakovVasilii_Github.yahoo.com/prefs.js:134:7
  _init@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:209:40
  OpenExtensionPrefsAsync/<@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:122:28
  asyncCallback@resource:///org/gnome/gjs/modules/core/overrides/Gio.js:115:22
  run@resource:///org/gnome/Shell/Extensions/js/dbusService.js:177:20
  main@resource:///org/gnome/Shell/Extensions/js/main.js:19:13
  run@resource:///org/gnome/gjs/modules/script/package.js:206:19
  start@resource:///org/gnome/gjs/modules/script/package.js:190:8
  @/usr/share/gnome-shell/org.gnome.Shell.Extensions:1:17