github-ci: use host cgroup namespace for live tests

Allow nested Podman containers to access the pids cgroup controller in
the privileged namespace test job.

Author: jasonish

.github/workflows/builds.yml

@@ -2001,7 +2001,7 @@ jobs:
     needs: [prepare-deps, prepare-cbindgen]
     container:
       image: ubuntu:24.04
-      options: --privileged
+      options: --privileged --cgroupns=host
     steps:
       - name: Cache ~/.cargo
         uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9