Add gurobi 11

Maybe to merge before the externals which would install only gurobi 11, I suppose

ci/setup_spack.sh

@@ -74,7 +74,7 @@ do
   done
 done
 
-if [ -d cp -r "${STACK_CONFIG_PATH}/templates" ${SPACK_SYSTEM_CONFIG_PATH} ]
+if [ -d "${STACK_CONFIG_PATH}/templates" ]
 then
    cp -r "${STACK_CONFIG_PATH}/templates" ${STACK_LOCATION}/spack/share/spack
 fi