fix: ansible truthy handling

[Nemental]

With the new Ansible version 2.19, something changes in handling with true/false values, which is why the molecule tests fail.

https://github.com/ansible-collections/community.grafana/actions/runs/14622246579/job/41025024595?pr=419

  TASK [Set async_dir for HOME env] **********************************************
  [ERROR]: Task failed: Conditional result was '/home/runner' of type 'str', which evaluates to True. Conditionals must have a boolean result.
  
  Task failed.
  Origin: /opt/hostedtoolcache/Python/3.12.10/x64/lib/python3.12/site-packages/molecule_plugins/docker/playbooks/destroy.yml:10:7
  
   8     - always
   9   tasks:
  10     - name: Set async_dir for HOME env
           ^ column 7
  
  <<< caused by >>>
  
  Conditional result was '/home/runner' of type 'str', which evaluates to True. Conditionals must have a boolean result.
  Origin: /opt/hostedtoolcache/Python/3.12.10/x64/lib/python3.12/site-packages/molecule_plugins/docker/playbooks/destroy.yml:13:13
  
  11       ansible.builtin.set_fact:
  12         ansible_async_dir: "{{ lookup('env', 'HOME') }}/.ansible_async/"
  13       when: (lookup('env', 'HOME'))
                 ^ column 13
  
  Broken conditionals can be temporarily allowed with the `ALLOW_BROKEN_CONDITIONALS` configuration option.
  
  fatal: [localhost]: FAILED! => {"changed": false, "msg": "Task failed: Conditional result was '/home/runner' of type 'str', which evaluates to True. Conditionals must have a boolean result."}

Fixes #311

[felixfontein]

@ssbarnea can you take a look at this PR?

[evgeni]

isn't it more correct to check the string length? something like

Suggested change

	when: lookup('env', 'HOME') is truthy
	when: lookup('env', 'HOME') | length > 0

[evgeni]

probably also applies to the other checks that do strings?

[Nemental]

I guess it's a matter of personal preference... I like is truthy little bit more because it checks if it's defined and not 0, empty, null etc.
But I'm not the one who decides :)