ci: Reduce the number of integration tests we run concurrently

Since there's a bunch of CPU hungry systemd-journal-remote processes
running on the host to received the forwarded logs, by running as many
test as the VM has cores we overload the available resources. Let's leave
use the number of cores - 1 to reduce resource contention.

diff --git a/.github/workflows/mkosi.yml b/.github/workflows/mkosi.yml
index 22e084bf7b38f2d9981e13035fab0938b3fdaf7b..eed78696f3a7322dced8648fc4dbefd803a30295 100644 (file)
--- a/.github/workflows/mkosi.yml
+++ b/.github/workflows/mkosi.yml
@@ -180,7 +180,7 @@ jobs:
       run: meson compile -C build mkosi
 
     - name: Run integration tests
-      run: meson test -C build --no-rebuild --suite integration-tests --print-errorlogs --no-stdsplit
+      run: meson test -C build --no-rebuild --suite integration-tests --print-errorlogs --no-stdsplit --num-processes "$(($(nproc) - 1))"
 
     - name: Archive failed test journals
       uses: actions/upload-artifact@v4