Get a list of task files and run them

taskfiles.yml

- hosts: somehosts
  become: yes

  tasks:
    - name: Get list of task files
      find:
        paths: /opt/ansible/tasks
        patterns: '*.yml'
      register: _task_files

    - name: Include tasks
      include: "{{ task_file.path }}.yml"
      loop_control:
        loop_var: task_file
      with_items: "{{ _task_files.files }}"