CMake: Google Test: properly unset IWYU/clang-format
CMake: Google Test: properly unset IWYU/clang-format

that is an external code, no point in checking it

LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed