Change use of 'multicore' CI runner

* build:main now uses default runner
* test:parallel now uses multicore runner

.gitlab-ci.yml

@@ -84,14 +84,10 @@ prep:update-dune-clang:
 # --- Build jobs ---
 build:main:
   stage: build
-  tags:
-    - multicore
   script:
     - CMAKE_FLAGS="$CMAKE_FLAGS"
-      MAKE_FLAGS="$MAKE_FLAGS"
       $DUNECONTROL --only=dorie all
-    - MAKE_FLAGS="$MAKE_FLAGS"
-      $DUNECONTROL --only=dorie make build_tests
+    - $DUNECONTROL --only=dorie make build_tests
   artifacts:
     name: "$CI_JOB_NAME"
     paths:
@@ -107,8 +103,7 @@ build:debug: &debug
         -DCMAKE_BUILD_TYPE=Debug 
         -DCMAKE_CXX_FLAGS_DEBUG='-Werror'"
       $DUNECONTROL --only=dorie configure
-    - MAKE_FLAGS="$MAKE_FLAGS"
-      $DUNECONTROL --only=dorie make dorie_mass_conservation
+    - $DUNECONTROL --only=dorie make dorie_mass_conservation
 
 build:debug-clang:
   <<: *debug
@@ -121,8 +116,7 @@ build:debug-clang:
         -DCMAKE_CXX_COMPILER=clang++
         -DCMAKE_CXX_FLAGS_DEBUG='-Werror'"
       $DUNECONTROL --only=dorie configure
-    - MAKE_FLAGS="$MAKE_FLAGS"
-      $DUNECONTROL --only=dorie make dorie_mass_conservation
+    - $DUNECONTROL --only=dorie make dorie_mass_conservation
 
 
 # --- Tests ---
@@ -147,6 +141,8 @@ test:ode:
 
 test:parallel:
   <<: *test
+  tags:
+    - multicore
   script:
     - $DUNECONTROL --only=dorie configure
     - $DUNECONTROL --only=dorie make test_run_parallel