`cmake_minimum_required` version is too old

[whitslack]

Since the CMake 3.31 release, this warning is shown by CMake:

CMake Deprecation Warning at CMakeLists.txt:5 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  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.

Gentoo is already emitting a QA warning when building packages that specify minimum CMake versions older than 3.10, as these packages will break upon an upcoming CMake release. See the Gentoo tracker for this issue.

Please bump your cmake_minimum_required to some version ≥3.10. Be aware that this will change some policy defaults.