[improve][ci] Cleanup tune-runner-vm and clean-disk actions

[lhotari]

Motivation

The tune-runner-vm and clean-disk GitHub Actions are outdated for the current Ubuntu 24.04 runners. Several services and commands referenced no longer exist (php7.4/8.0-fpm, mono-xsp4, cgget), causing unnecessary error messages in CI logs. The clean-disk action also lacks flexibility — it always performs full cleanup regardless of available disk space.

Modifications

tune-runner-vm:

• Remove obsolete service stops (php7.4/8.0-fpm, mono-xsp4, mono, walinuxagent) and replace with current services (php8.3-fpm, ModemManager, multipathd, udisks2)
• Keep walinuxagent.service stop since the tuning script stops it at runtime
• Remove obsolete cgroup v1 swappiness settings (cgroup v2 is used on current runners)
• Disable unnecessary timers (podman-auto-update, sysstat-collect, sysstat-summary, phpsessionclean, man-db, motd-news, dpkg-db-backup, e2scrub_all, update-notifier-download, update-notifier-motd)
• Remove cgget cgroup info block (cgget not available on current runners)
• Change THP defrag from defer+madvise to defer per Netflix's ZGC tuning recommendation
• Guard /mnt remount with mountpoint -q /mnt check

clean-disk:

• Add clean-threshold-gb (default: 20) and full-clean-threshold-gb (default: 40) parameters to skip cleanup when sufficient disk space is available
• Early exit if disk space already meets threshold
• Delete directories one at a time, rechecking threshold between each step
• Guard /mnt-related operations with mountpoint -q /mnt check
• Refactor to use shell functions (available_gb, show_disk, remove_dir, clean_dirs) to reduce duplication
• Bind inputs to env vars following best practices for composite actions

Verifying this change

• Make sure that the change passes the CI checks.

This change is already covered by existing tests — the CI workflows that use these actions will validate the changes.

Does this pull request potentially affect one of the following parts:

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• The metrics
• Anything that affects deployment

Documentation

• doc-not-needed

[lhotari]

/pulsarbot rerun-failure-checks

[lhotari]

/pulsarbot rerun-failure-checks