pietro@kube0:~ $ cat playbooks/apt-upgrade.yml
- hosts: all
  become: yes
  tasks:
   - name: update
     apt: update_cache=yes force_apt_get=yes cache_valid_time=3600
     cache_valid_time: 86400 #One day
pietro@kube0:~ $ ansible-playbook playbooks/apt-upgrade.yml
ERROR! 'cache_valid_time' is not a valid attribute for a Task

The error appears to have been in '/home/pietro/playbooks/apt-upgrade.yml': line 4, column 6, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

  tasks:
   - name: update
     ^ here

This error can be suppressed as a warning using the "invalid_task_attribute_failed" configuration
pietro@kube0:~ $ ansible --version
ansible 2.7.7
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/pietro/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.7.3 (default, Jan 22 2021, 20:04:44) [GCC 8.3.0]
pietro@kube0:~ $