ci: tests: api test-switch-window sporadically fails on Safari

[Lee Read]

We get sporadic failures for etaoin.api-test/test-switch-window on macOS Safari.

I played around in the REPL which helped me to remember that safaridriver is not always great with the mouse click, and this is how we trigger our 2nd window to be created.

I'll trigger 2nd window creation with, maybe, an Enter key.