Configuring with CMake causes build-system warnings

When configuring with cmake version 3.27 (and perhaps earlier versions as well), this warning is issued:

CMake Deprecation Error at external/argh/CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.5 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.

To Reproduce

Configure argh using cmake

cmake -B build -S .

Expected behavior

No warnings on cmake configure.

Environment

Tested on Fedora Linux, but this probably manifests on all operating systems.

Additional context

• CMake 3.1.0 was released on Dec 17, 2014
• CMake 3.5.0 was released on Mar 8, 2016
• Latest release is 3.28.3 which was Feb 5, 2024