z3: update package to use CMake build system (#24337)
z3: update package to use CMake build system (#24337)

The Z3 solver provides a Z3Config.cmake file when built using the CMake build
system. This submission changes the package build system to inherit the
CMakePackage type. In addition to changing the build system, this submission:

- Adds the GMP variant
- Removes v4.4.0 and v4.4.1 as CMake was implemented starting with v4.5.0
LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack