Drop iOS 15

[LePips]

Stub for dropping iOS 15 after 1.3 release.

• Document support "ideal" (n - 2)

[eisams]

FYI: There's no devices that would lose support if you were to require tvOS 18 compared to the current tvOS 15, so you could consider bumping the minimum further if that makes overall development easier

(sorry, slightly tired so I read this as tvOS and not iOS... )

In the specific case of iOS, iOS 16 do not receive security updates, that requires iOS 17
In addition, all devices that support iOS 17 also support iOS 18, so you could bump to iOS 18 if you wish to keep the minimum to versions receiving security updates (normally current + previous iOS)

https://en.wikipedia.org/wiki/TvOS#Supported_OS_releases

[LePips]

Thank you, I have made that observation before: #1076 (comment)

When we drop iOS 16, probably later this year to keep up with an n-2 support policy, we can make the jump to iOS 18 due to the supported devices. tvOS will most likely happen sooner.