[settings] Update Apple OS versions list

[uilianries]

Changelog: Feature: Support newer Apple OS versions: 15.8 and 26.7
Docs: Omit

Apple had a recent security release, which affected all its operating systems: https://support.apple.com/en-us/100100

About these new versions listed in this PR:

• WatchOS 8.8: https://support.apple.com/en-us/118389
• WatchOS SDK 26.6: https://developer.apple.com/documentation/watchos-release-notes/watchos-26_6-release-notes
• MacOS 15.8 Sequoia: https://support.apple.com/en-us/149043
• MacOS 26.7 Tahoe: https://support.apple.com/en-us/149042
• MacOS 26.6 Tahoe: https://support.apple.com/en-us/148281
• MacOS 14.8 Sonoma: https://support.apple.com/en-us/148172
• MacOS SDK 26.6: https://developer.apple.com/documentation/macos-release-notes/macos-26_6-release-notes#Overview

closes #20344
/cc @Nekto89

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