Google’s YouTube and Spotify Technology SA, the world’s most popular video and music services, are joining Netflix Inc. in steering clear of Apple Inc.’s upcoming mixed-reality headset.YouTube said in a statement Thursday that it isn’t planning to launch a new app for the Apple Vision Pro, nor will it allow its longstanding iPad application to work on the device. YouTube, like Netflix, is recommending that customers use a web browser if they want to see its content: “YouTube users will be able t...