Fix iOS build, and add iOS step to CI

[lucasmerlin]

This PR

• adds a pipeline to check the ios build
• removes the iOS WaitUntil workaround, which doesn't seem to be necessary anymore after the winit update (and caused the build for iOS to fail again because of a missing self
• removes a iOS workaround for window size which doesn't seem necessary anymore
  Turns out it was still needed (but you need to actually restart the app for the issue to show up, so I didn't catch it first)
• fixes some cargo check errors in run.rs

I've done all these changes in a single PR because otherwise the pipeline doesn't run but I can also split them in separate PRs if that makes it easier to review

[emilk]

Thanks! Looks good, but CI is red

[lucasmerlin]

@emilk finally got around to fixing the lint warnings, sorry it took so long

[emilk]

Thanks!