Hi. Currently I have an iPhone 6 that I never upgraded past iOS 9.3.5. It runs well and I don’t need any of the features added since then (the security updates would be nice but are not as important to me as performance), so I’d prefer not updating it. I’d like to get an apple watch. Will I need to update my iPhone to pair it to a watch? Is there a watch version that will work with my phone? I’d reluctantly be ok with updating my phone if I need to, but if iOS 12 negatively impacts my phone's overall performance I’d likely just get a new phone instead of a watch. Thanks!