limit parallelism

Author: rarescosma

tests/common/install-tools.bash

@@ -203,7 +203,7 @@ do_unit() {
 
   git config --global advice.detachedHead false
 
-  parallel --will-cite --halt now,fail=1 ::: \
+  parallel -j "$(nproc)" --will-cite --halt now,fail=1 ::: \
     install_bats \
     install_docs \
     install_gomplate \
@@ -221,7 +221,7 @@ do_unit() {
 
 do_main() {
   echo "Installing main tools in parallel..."
-  parallel --will-cite --halt now,fail=1 ::: \
+  parallel -j "$(nproc)" --will-cite --halt now,fail=1 ::: \
     install_kind \
     install_velero \
     install_bun