xcode+cmake: Use SDL3.framework/SDL3 as IMPORTED_LOCATION
Not adding /SDL3 causes CMake to no longer set the RUNPATh on
binaries in the build directory.
It also breaks compatibility with CMake versions older then 3.28.
reverts c56a3f60fe88e9c8b13d7bfd92363e5d2c9a152f (xcode+cmake: use SDL3.framework folder as IMPORTED_LOCATION)
reverts ad3c7b92f8726816580033fdaeb52933419102b8 (xcode+cmake: use SDL3.framework folder as IMPORTED_LOCATION)