macOS: Replace deprecated Q_OS_MAC with Q_OS_MACOS


Q_OS_MAC is a deprecated synonym for Q_OS_DARWIN (= Q_OS_APPLE), but
predates Qt's support for iOS and the other Apple platforms. The
hard-coded system theme colors matching OSX 10.7 are macOS-specific.

Change-Id: I4e60cc95b0b40e35d9d0ea0a70911229b98b0d09
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
commit4fff81e6c7580d359db7f55806c95f52e8b82337
parent759310e94e2793c02794d260e91fda8ab837feab
authorTor Arne Vestbø <tor.arne.vestbo@qt.io>
committerTor Arne Vestbø <tor.arne.vestbo@qt.io>
commit timeThu, 9 Apr 2026 21:36:21 +0200