This is deprecated in macOS 11, so we should remove it.

• It's used for the styleMask in shell/browser/ui/cocoa/electron_inspectable_web_contents_view.mm
• It's used in for the styleMask in shell/browser/native_window_mac.mm -[ BaseWindowConstructorOptions.typeoftextured](https://github.com/electron/electron/blame/87fb2ad70cf778752aadc5496f534b7a0793da61/docs/api/structures/base-window-options.md#L143) maps to this value & should be removed -[ ] I think we'd also remove the [kStandardWindow` option](

  electron/shell/browser/native_window_mac.mm

  Line 204 in 87fb2ad

  options.Get(options::kStandardWindow, &useStandardWindow);

  ) which (a) has a comment saying we should deprecate it, and (b) seems to be unused + undocumented, and (c) is related to opting-out of a textured background that we won't be able to use anymore