MacOS: Where are default keyboard layouts located?

As I understand, you can place custom keyboard layouts in /Library/Keyboard Layouts and ~/Library/Keyboard Layouts/ in MacOS, and they pop-up in the “Keyboard” section of Settings.

I want to observe, read, and edit one of the default keyboard layouts (Dvorak-Cmd-Qwerty). I expect it to be an XML file. Where is it located?

Tldr Where are default MacOS keyboard layouts located?