common-utils: Add sandboxing dependencies and distro coverage

[Christof Marti (chrmarti)]

Summary

• Install slirp4netns, util-linux, and iptables alongside bubblewrap for sandboxing and sandbox networking.
• Keep bubblewrap/slirp4netns optional where RPM repositories do not provide them, with explicit skip messages. Query after enabling EPEL and use microdnf repoquery on minimal images (microdnf list is unsupported).
• Extend command/version checks across the configured distro/version scenarios, including Debian, older Alpine releases, CentOS, AlmaLinux/Rocky minimal images, Mariner, Azure Linux, and UBI.
• Update the included-utilities notes and bump common-utils to 2.7.1.

Validation

• All 25 modified shell scripts pass bash -n; git diff --check passes.
• Generic feature tests passed on Ubuntu Jammy, Alpine 3.18, and Rocky Linux 9.
• All 16 newly covered scenarios passed across the full run and targeted reruns: Bookworm, Trixie, CentOS 7, AlmaLinux 8, AlmaLinux 8/9 minimal, Rocky Linux 8, Rocky Linux 8/9 minimal, Mariner 2.0, Azure Linux 3.0, UBI 8.10, Alpine 3.14/3.15/3.18, and the Alpine devcontainer base.
• The initial minimal-image failures exposed the unsupported microdnf query. After fixing it, all seven targeted RPM regression scenarios passed.
• Local tests used LF-normalized temporary copies because the Windows checkout uses CRLF. UID remapping was disabled only in temporary scenario configurations to avoid mapping test users to the WSL host's root UID; repository scenarios are unchanged.

Reviewer notes

• Mariner/Azure Linux currently lack slirp4netns, and UBI 8 lacks bubblewrap. Their tests check repository availability and explicitly report these expected skips; repository-query failures are not silently ignored.
• Tests verify command availability/version output, not functional sandbox execution.
• Existing CI coverage is unchanged: no common-utils ARM64 matrix was added, and existing continue-on-error settings remain unchanged.