CMake: remove `ZIG_USE_CCACHE` option
Not really useful after old C++ compiler removal, and
zig build has own cache system. If someone still wants it,
`CMAKE_C_COMPILER_LAUNCHER` and `CMAKE_CXX_COMPILER_LAUNCHER` exist.
From CMake docs:
> RULE_LAUNCH_COMPILE
> Note: This property is intended for internal use by ctest(1).
> Projects and developers should use the <LANG>_COMPILER_LAUNCHER
> target properties or the associated CMAKE_<LANG>_COMPILER_LAUNCHER
> variables instead.
Signed-off-by: Eric Joldasov <bratishkaerik@landless-city.net>