Alternative layout can't have deadkeys if main layout doesn't have

[snomos]

Cf keyboard-sjd. The main layout file, sjd.yaml, is based on the standard Russian keyboard layout, which does not include any deadkeys.

We then added an alternative layout, sjd-NO.yaml, based on a Norwegian layout, to make it easier to researchers in Norway to write SJD. This layout contains deadkeys, but we could not make them work. Instead we got warnings like:

2023-10-07T11:46:41.342697Z  WARN kbdgen::build::macos::generate_macos: No transforms in sjd:MacOS:Primary

Only after we added deadkeys to the primary layout would the deadkeys in the secondary layout work.

The layout was made by me and @Trondtr .