Fix Mactrack integration dependencies

[somethingwithproof]

Summary

• avoid unavailable Ubuntu-versioned Apache PHP packages
• install Mactrack runtime Composer dependencies before plugin enablement

Validation

• git diff --check
• workflow YAML parsed successfully

This is deliberately separate from #336 so the release-hardening change remains focused.

[Copilot]

Pull request overview

Updates the GitHub Actions integration workflow to be less dependent on Ubuntu’s apt-provided Apache/PHP module packaging and to ensure Mactrack’s Composer-managed runtime dependencies (when present) are installed before the plugin is enabled in the Cacti E2E flow.

Changes:

• Remove libapache2-mod-php${{ matrix.php }} from apt dependencies to avoid unavailable Ubuntu-versioned packages.
• Add a workflow step to run composer install --no-dev in the Mactrack plugin directory (guarded by composer.json existence) prior to plugin enablement.

[somethingwithproof]

Copilot's vendor-scope comment was already addressed by c7eda37/601a787 (find . -path './vendor' -prune -o ... | xargs php -l). Also confirmed the plugin has no composer.json yet, so the "Install Mactrack Composer Dependencies" step is currently a no-op and no vendor tree gets created either way. Resolved the thread; no code change needed.

[somethingwithproof]

Closing as superseded by current develop. After rebasing, all substantive integration-dependency and vendor-exclusion changes are already present; replaying the remaining historical commits would remove newer CI safeguards.