Don't mess around with DUNECI_PARALLEL

.gitlab-ci.yml

@@ -3,12 +3,8 @@ variables:
   GIT_SUBMODULE_STRATEGY: recursive
 
 before_script:
-- echo "Running make concurrently with $(nproc) cores, where possibly"
+- echo "Running make concurrently with ${DUNECI_PARALLEL} cores, where possibly"
 - patches/apply_patches.sh
-# detect number of processors, but make sure never to run with -j"", as the
-# build host would likely run out of memory
-- ": ${DUNECI_PARALLEL:=$(nproc || echo 1)}"
-- export DUNECI_PARALLEL
 
 git--gcc:
   image: registry.dune-project.org/joe/dune-perftool-ci/perftool-base:git