The proprietary firmware for the darp9 adds the mic mute hotkey using the new "Call Mute" hotkey from Windows 11 22H2, which is mapped to `Super+Alt+K` [1]. Match the behavior in open firmware. [1]: https://support.microsoft.com/en-us/windows/keyboard-shortcuts-in-windows-dcc61a57-8ff0-cffe-9796-cb9706c75eec#WindowsVersion=Windows_11 Signed-off-by: Tim Crawford <tcrawford@system76.com>