:electron: Remove "About" screen and broken updater (#2983)

packages/desktop-electron/about.js

packages/desktop-electron/about/about.html

packages/desktop-electron/about/index.js

packages/desktop-electron/index.ts

packages/desktop-electron/menu.ts

packages/desktop-electron/package.json

packages/desktop-electron/preload.js

packages/desktop-electron/updater.js

packages/loot-core/src/server/main.ts

packages/loot-core/src/types/prefs.d.ts

upcoming-release-notes/2983.md

yarn.lock