Actions: Add netcdf bin path before installing mhkit-python

.github/workflows/unix_unit_tests.yml

@@ -255,6 +255,7 @@ jobs:
         shell: bash -l {0}
         run: |
           conda activate mhkit_conda_env
+          export PATH="${CONDA_PREFIX}/bin:${CONDA_PREFIX}/Library/bin:$PATH" # so setup.py finds nc-config
           pip install -e .
 
       - name: pip install mhkit-python-utils module from source