Remove the apptainer workaround for 24.04

This reverts commit 3f005da821.

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

templates/apptainer.yaml

@@ -17,9 +17,6 @@ provision:
     #!/bin/bash
     set -eux -o pipefail
     command -v apptainer >/dev/null 2>&1 && exit 0
-    # Workaround for https://github.com/apptainer/apptainer/issues/2027
-    echo "kernel.apparmor_restrict_unprivileged_userns = 0" >/etc/sysctl.d/99-userns.conf
-    sysctl --system
     # add the "Official PPA for Apptainer"
     add-apt-repository -y ppa:apptainer/ppa
     apt-get update