Merge pull request #134 from billsacks/derecho_pfunit

Add pFUnit support on derecho with the intel compiler

I built and installed pFUnit as follows:

```
git clone [email protected]:Goddard-Fortran-Ecosystem/pFUnit.git
cd pFUnit
git describe --tags
# that shows v4.8.0
export PFUNIT=$CESMDATAROOT/tools/pFUnit/pFUnit4.8.0_derecho_Intel2023.2.1_noMPI_noOpenMP
mkdir build-dir
cd build-dir
/glade/work/sacks/ctsm_code/ctsm/cime/CIME/scripts/configure --mpilib mpi-serial
source ./.env_mach_specific.sh
cmake -DSKIP_MPI=YES -DSKIP_OPENMP=YES -DCMAKE_INSTALL_PREFIX=$PFUNIT ..
make -j 8
make tests
make install
```

Note that this used the following modules:

```
Currently Loaded Modules:
  1) cesmdev/1.0   (H,S)   3) craype/2.7.23    5) mkl/2023.2.0          7) cmake/3.26.3       9) hdf5/1.12.2   11) parallelio/2.6.2
  2) ncarenv/23.09 (S)     4) intel/2023.2.1   6) ncarcompilers/1.0.0   8) mpi-serial/2.3.0  10) netcdf/4.9.2  12) esmf/8.6.0b04
```

I tested in the context of the latest CTSM master by running the following from the src directory with this change in place:
```
../cime/scripts/fortran_unit_testing/run_tests.py --build-dir unit_tests.temp
```

All CTSM unit tests built & passed.

Resolves #131 - fyi @ekluzek

machines/cmake_macros/intel_derecho.cmake

@@ -7,5 +7,8 @@ endif()
 if (COMP_NAME STREQUAL mpi-serial)
   string(APPEND CFLAGS " -std=c89 ")
 endif()	
+if (MPILIB STREQUAL mpi-serial AND NOT compile_threaded)
+  set(PFUNIT_PATH "$ENV{CESMDATAROOT}/tools/pFUnit/pFUnit4.8.0_derecho_Intel2023.2.1_noMPI_noOpenMP")
+endif()
 set(SCC icx)
 set(SFC ifort)