CMakeLists.txt: use min...max notation

[graysky2]

Using this future proofs the build and surpresses a harmless but annoying warning:

CMake Deprecation Warning at 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.

-- The C compiler identification is GNU 12.1.0
-- The CXX compiler identification is GNU 12.1.0
...

[macmpi]

same goes for each individual app directory CMakeLists.txt

[pelwell]

I'll take your words on this - it still builds for me.