build fails with cmake 4

[andrewzah]

       > CMake Error at CMakeLists.txt:20 (cmake_minimum_required):
       >   Compatibility with CMake < 3.5 has been removed from CMake.
       >
       >   Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
       >   to tell CMake that the project requires at least <min> but has been updated
       >   to work with policies introduced by <max> or earlier.
       >
       >   Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.
       >
       >

the fix is to update CMakeLists.txt:

cmake_minimum_required(VERSION 3.10)