kxstitch: Fix the snap so it runs now.

Added missing stage time library dependency. Also changed the version back to 2.2.0 for now. Somehow using git failed to build locally because in the container there's no .git folder somehow...

@scarlettmoore I can change that back to git if that works on CI, not sure why it doesn't work locally.

I'm also seeing some strangeness in the ui. the & characters in groupboxes isn't getting changed into alt- keyboard shortcuts somehow. Do I need some plug or something else to make that work correctly? It's working right in the menus, just not the groupboxes.

See P&review, P&allette and H&istory on the left in this screenshot.