The systemd package got a security update in Debian trixie, which
changed the systemd-coredump kernel sysctl core_pattern value (by
appending « %d %F»). This is part of the fix for CVE-2025-4598.
This has caused ngcp-system-tests to fail to match the new pattern,
so we need to adapt it for all currently supported Debian trixie
releases.
In addition for Debian trixie, a new enough Linux kernel is required
to benefit from the full security fix.
Ref: https://security-tracker.debian.org/tracker/CVE-2025-4598
Ref: 2eb46dce07
Change-Id: I89e6ff1d084403e6ae4b4eca6f5606b0d2417c01