set default NUM_JOBS value to be the same accross all scripts (#1688)

ci/install-verilator.sh

@@ -3,8 +3,8 @@
 ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
 cd $ROOT/tmp
 
-if [ -z ${NUM_JOBS} ]; then
-    NUM_JOBS=4
+if [ -z "$NUM_JOBS" ]; then
+    NUM_JOBS=1
 fi
 
 VERILATOR_REPO="https://github.com/verilator/verilator.git"

verif/regress/install-cva6.sh

@@ -63,9 +63,6 @@ else
   echo "Skipping Verilator setup on user's request (\$VERILATOR_INSTALL_DIR = \"NO\")."
 fi
 
-# number of parallel jobs to use for make commands and simulation
-export NUM_JOBS=24
-
 # install the required tools for cva6
 if [ -z "$CVA6_REPO" ]; then
   CVA6_REPO="https://github.com/openhwgroup/cva6.git"

verif/regress/install-verilator.sh

@@ -8,7 +8,7 @@
 # Original Author: Jean-Roch COULON - Thales
 
 if [ -z "$NUM_JOBS" ]; then
-    NUM_JOBS=4
+    NUM_JOBS=1
 fi
 
 # Ensure the location of tools is known (usually, .../core-v-verif/tools).