setup.sh should set CMAKE_PREFIX_PATH and BOOST_ROOT

[kjmeagher]

to compile nuflux on cvmfs you need to set the env vars CMAKE_PREFIX_PATH=${SROOT} BOOST_ROOT=${SROOT}. It would cut down on user frustration if these were set by setup.sh. See icecube/nuflux#24 (comment)

[dsschult]

@kjmeagher

When I set BOOST_ROOT, icetray complains during tool detection with

CMake Warning (dev) at cmake/tools/boost.cmake:49 (find_package):
  Policy CMP0144 is not set: find_package uses upper-case <PACKAGENAME>_ROOT
  variables.  Run "cmake --help-policy CMP0144" for policy details.  Use the
  cmake_policy command to set the policy and suppress this warning.

  Environment variable BOOST_ROOT is set to:

    /home/dschultz/cvmfs_build/py3-v4.4.0/Ubuntu_24.04_aarch64

  For compatibility, find_package is ignoring the variable, but code in a
  .cmake module might still use it.
Call Stack (most recent call first):
  cmake/tools.cmake:71 (include)
  CMakeLists.txt:111 (include)
This warning is for project developers.  Use -Wno-dev to suppress it.

[kjmeagher]

So we now provide wheels for nuflux, and the people that were compiling it for use with c++ appeared to have moved on to other realizations of atmospheric fluxes. So it is not clear if this is necessary anymore. Unless @nega0 thinks it is a good idea to set BOOST_ROOT we don't need to any more