---
- name: Set stats test
  hosts: all
  become: true
  gather_facts: false

  tasks:
    - name: Test a var
      ansible.builtin.set_stats:
        data:
          test_set_stats: "It works!"
        per_host: false

    - name: Debug test_set_stats
      ansible.builtin.debug:
        var: test_set_stats

...