Fix macOS warning on cmake project initialization

Author: aobolensk

CMakeLists.txt

@@ -1,5 +1,9 @@
 cmake_minimum_required( VERSION 3.25 )
 
+if(DEFINED CMAKE_OSX_SYSROOT AND NOT EXISTS "${CMAKE_OSX_SYSROOT}")
+  unset(CMAKE_OSX_SYSROOT CACHE)
+endif()
+
 message( STATUS "Parallel Programming Course (PPC)" )
 project(parallel_programming_course)