Bring virtual_servers up to the current ansible-role-sync template
and the ansible-core 2.20 baseline: preflight assertions, a
corrected defaults/vars split, a working Molecule scenario, and a
documented public interface.

* bump min_ansible_version to 2.20 (was 2.12); meta/main.yml drops
  the dead galaxy_info.platforms key and folds OS/version support
  into description instead
* add tasks/preflight.yml, wired first in tasks/main.yml: asserts
  ansible-core >= 2.20, supported OS family, keep_build_essentials
  is boolean, and fact_end_of_life is defined on RedHat hosts
* move OS-specific package lists from defaults/Debian.yml and
  defaults/RedHat.yml to vars/Debian.yml and vars/RedHat.yml so
  include_vars/first_found loads them as intended; vars/ has
  different override precedence than defaults/, so any consumer
  overriding official_vmware_tools, official_virtualbox_tools,
  official_openvz_tools, official_proxmox_tools, open_vmware_tools,
  or build_tools via group_vars/host_vars needs a higher-precedence
  override instead
* add the missing keep_build_essentials: false default; it was
  referenced in tasks/vmware/main.yml and documented in the README
  but never actually defined, so any consumer that did not set it
  hit an undefined-variable error
* drop past-EOL platforms from the supported-platform statement:
  Ubuntu bionic, xenial, focal, and Debian bullseye
* remove tasks/vmware/install-official-vmware-tools.yml and
  tasks/vmware/remove-official-vmware-tools.yml, both fully
  disconnected from tasks/main.yml and never executed
* remove unused defaults/Suse.yml; SUSE was never wired into
  tasks/, so this was dead data
* fix molecule/default/converge.yml, which previously had an empty
  roles list and never exercised the role during molecule converge;
  it now references the role by its own directory basename
* switch the Molecule verifier from Ansible to testinfra, rewrite
  the platform matrix to jammy/noble/resolute, bookworm/trixie, and
  EL 9, and add a pytest-testinfra suite under molecule/default/tests
* add requirements.yml declaring the amazon.aws collection, required
  by the existing ec2_metadata_facts task but never previously
  declared
* add meta/argument_specs.yml documenting keep_build_essentials
* add CLAUDE.md and TODO.md; see TODO.md for follow-up items
  (orphaned vmware-repo.j2 template, untestable guest-tools branches
  under the Docker Molecule driver, no DESIGN.md yet)

BREAKING CHANGE: min_ansible_version is now 2.20 (was 2.12).
official_vmware_tools, official_virtualbox_tools,
official_openvz_tools, official_proxmox_tools, open_vmware_tools,
and build_tools moved from defaults/ to vars/, changing their
override precedence -- group_vars/host_vars overrides of these will
silently stop applying; use a higher-precedence override instead.
The supported-platform statement no longer includes Ubuntu bionic,
xenial, focal, or Debian bullseye.