Update OpenMPI oversubscribe flags in configs/containers/docker-ubunt…

…u-gcc-openmpi.yaml for openmpi@5:

configs/containers/docker-ubuntu-gcc-openmpi.yaml

@@ -177,22 +177,22 @@ spack:
         echo "export CXX=g++" >> /home/nonroot/.bashrc && \
         echo "export FC=gfortran" >> /home/nonroot/.bashrc && \
         printf "[credential]\n    helper = cache --timeout=7200\n" >> /home/nonroot/.gitconfig && \
-        mkdir /home/nonroot/.openmpi && \
-        echo "rmaps_base_oversubscribe = 1" >> /home/nonroot/.openmpi/mca-params.conf && \
-        chown -R nonroot:nonroot /home/nonroot/.gitconfig /home/nonroot/.openmpi
+        mkdir /home/nonroot/.pmix && \
+        echo "rmaps_default_mapping_policy=:oversubscribe" >> /home/nonroot/.pmix/mca-params.conf && \
+        chown -R nonroot:nonroot /home/nonroot/.gitconfig /home/nonroot/.pmix
         # Replicate settings for root user
         RUN echo "ulimit -s unlimited" >> /root/.bashrc && \
         echo "ulimit -v unlimited" >> /root/.bashrc && \
         echo "export CC=gcc" >> /root/.bashrc && \
         echo "export CXX=g++" >> /root/.bashrc && \
         echo "export FC=gfortran" >> /root/.bashrc && \
         printf "[credential]\n    helper = cache --timeout=7200\n" >> /root/.gitconfig && \
-        mkdir /root/.openmpi && \
-        echo "rmaps_base_oversubscribe = 1" >> /root/.openmpi/mca-params.conf
+        mkdir /root/.pmix && \
+        echo "rmaps_default_mapping_policy=:oversubscribe" >> /root/.pmix/mca-params.conf
         # Also set necessary environment variables for openmpi
         RUN echo "export OMPI_ALLOW_RUN_AS_ROOT=1" >> /root/.bashrc && \
         echo "export OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1" >> /root/.bashrc && \
-        echo "export OMPI_MCA_rmaps_base_oversubscribe=1" >> /root/.bashrc
+        echo "export PRTE_MCA_rmaps_default_mapping_policy=:oversubscribe" >> /root/.bashrc
 
     # Labels for the image
     labels: