ci: switches to a working OpenMPI for NVHPC

.gitlab-ci.yml

@@ -111,7 +111,14 @@ include:
     COMPILER_ID: nvhpc
   before_script:
     - *levante_basic_environment
-    - module load openmpi/4.1.6-nvhpc-23.9
+# There is no module for the working version of OpenMPI:
+    - export PATH="/sw/spack-levante/openmpi-4.1.4-3qb4sy/bin:$PATH"
+# The module for NVHPC 23.9 is unusable because it overrides CC and FC:
+    - export PATH="/sw/spack-levante/nvhpc-23.9-xpxqeo/Linux_x86_64/23.9/compilers/bin:$PATH"
+# The working version of OpenMPI is built and configured to work with NVHPC 22.5
+# but we want to use executables from the PATH:
+    - export OMPI_CC=nvc
+    - export OMPI_FC=nvfortran
 
 .init_build_levante_intel:
   extends: .init_build_levante