Merge branch 'mnowak/stress-test-drop-parallel-build' into 'main'

Drop parallel build from stress tests

See merge request isc-projects/bind9!7669

.gitlab-ci.yml

@@ -1362,12 +1362,16 @@ respdiff-long-third-party:
 
 # "Stress" tests
 
+# Parallel build in the "make" step is avoided since multiple jobs can be
+# executed concurrently on the same runner. This may present problems when one
+# job runs a performance-sensitive task of replying to queries while another
+# takes all cores to build BIND.
 .stress: &stress_job
   stage: performance
   script:
     - *configure
     - *setup_interfaces
-    - make -j${BUILD_PARALLEL_JOBS:-1} -k all V=1
+    - make -k all V=1
     - make DESTDIR="${INSTALL_PATH}" install
     - git clone --depth 1 https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.isc.org/isc-private/bind-qa.git
     - cd bind-qa/bind9/stress