cmake: Remove Ccache option to enforce second preprocessor call

Feature was removed in Ccache 4.12, which is provided by Homebrew by
default since 2025-10-19.

cmake/macos/resources/ccache-launcher-c.in

@@ -4,7 +4,6 @@ if [[ "$1" == "${CMAKE_C_COMPILER}" ]] ; then
     shift
 fi
 
-export CCACHE_CPP2=true
 export CCACHE_DEPEND=true
 export CCACHE_DIRECT=true
 export CCACHE_FILECLONE=true

cmake/macos/resources/ccache-launcher-cxx.in

@@ -4,7 +4,6 @@ if [[ "$1" == "${CMAKE_CXX_COMPILER}" ]] ; then
     shift
 fi
 
-export CCACHE_CPP2=true
 export CCACHE_DEPEND=true
 export CCACHE_DIRECT=true
 export CCACHE_FILECLONE=true