Update minimum OS versions to support Xcode 15

[luispadron]

This is a pre-requisite for Xcode 15+ adoption (#837). Supported versions are available here: https://developer.apple.com/support/xcode/

Changes:

• Update to add more minimum OS versions
• Update iOS versions <12.0 to use 12.0
• Update macOS versions <10.13 to use 10.13
• Update test host app versions to drop OS < 12.0