Projects: move CPPCHECK option to Athena project

ATLAS_USE_CPPCHECK was set in CxxUtils to ON but this should not be done for projects where we do not have cppcheck available. Move the setting to Athena and ensure it is propagated to downstream (i.e. WorkDir) projects.

Closes ATLINFR-5672.

Control/CxxUtils/cmake/CxxUtilsSettingsConfig.cmake

-# Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2025 CERN for the benefit of the ATLAS collaboration
 #
 # Additional CMake settings for the build. Used by Projects/.
 #
@@ -29,9 +29,6 @@ endif()
 set( ATLAS_GCC_CHECKERS_CONFIG ${_config}
    CACHE STRING "Configuration file(s) for the GCC checker plugins" FORCE )
 
-# CppCheck options:
-option( ATLAS_USE_CPPCHECK "Use CppCheck in the build" ON )
-
 # User-defined cppcheck command line options:
 set( ATLAS_CPPCHECK_OPTIONS "--enable=warning,portability,performance"
    CACHE STRING "cppcheck user-defined command line options" )