Describe the bug
After recently upgrading to macOS Big Sur (version 11.0.1), I am no longer able to toggle the traditional macOS fullscreen functionality that Kitty has previously supported with macos_traditional_fullscreen.

My full Kitty configuration is available here for reference.

To Reproduce
Steps to reproduce the behavior:

1. Set kitty.conf to:

macos_traditional_fullscreen yes
kitty_mod cmd
map kitty_mod+enter toggle_fullscreen 

2. Hit ⌘enter.
3. See the top menubar of macOS disappear without making the terminal fullscreen.

Expected behavior
Before the macOS upgrade, the same steps would have made the terminal fullscreen which I would have expected it to still do.

Environment details
OS: macOS Big Sur (version 11.0.1).

Output of kitty --debug-config

kitty 0.19.2 created by Kovid Goyal
Darwin libris.local 20.1.0 Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASE_X86_64 x86_64
ProductName:	macOS ProductVersion:	11.0.1 BuildVersion:	20B29
Loaded config files: /Users/mathias/.config/kitty/kitty.conf

Config options different from defaults:
kitty_mod                    8
macos_traditional_fullscreen True
Changed shortcuts:
	 super+enter KeyAction(func='toggle_fullscreen', args=())

Thank you for your great work on not only Kitty but also Calibre.