<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
After upgrade from 2.9.10 to 2.9.11 I noticed the module 'group_by' is reporting 'changed'.
This is because this change in #69860 
The problem is that it is reporting 'changed' even with `changed_when: false` added to the task.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
group_by

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9.11
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Ubuntu 18.04 (control and target host)

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
As an example use the task:
```
- group_by:
    key: "os_{{ ansible_facts['distribution_file_variety'] }}"
  changed_when: false
  register: groupby

- debug:
    msg: "{{ groupby }}"
```

```yaml
TASK [group_by_os : group_by] *******************************************************************************************************************************
changed: [srvd-test04]

TASK [group_by_os : debug] **********************************************************************************************************************************
ok: [srvd-test04] => 
  msg:
    add_group: os_Debian
    changed: true
    failed: false
    parent_groups:
    - all

PLAY RECAP **************************************************************************************************************************************************
srvd-test04                : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0 
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
The task should always return `changed: false`

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
The task return `changed: true`
<!--- Paste verbatim command output between quotes -->
```paste below

```

throttle = int(templar.template(task.throttle))
        except Exception as e:
            raise AnsibleError("Failed to convert the throttle value to an integer.", obj=task._ds, orig_exc=e)
        
        try:
            
            
            
            
            
            rewind_point = len(self._workers)
            if throttle > 0 and self.ALLOW_BASE_THROTTLING:
                if task.run_once:
                    display.debug("Ignoring 'throttle' as 'run_once' is also set for '%s'" % task.get_name())
                else:
                    if throttle <= rewind_point:
                        display.debug("task: %s, throttle: %d" % (task.get_name(), throttle))
                        rewind_point = throttle
            queued = False
            starting_worker = self._cur_worker
            while True:
                if self._cur_worker >= rewind_point:
                    self._cur_worker = 0
                worker_prc = self._workers[self._cur_worker]
                if worker_prc is None or not worker_prc.is_alive():
                    self._queued_task_cache[(host.name, task._uuid)] = {
                        'host': host,
                        'task': task,
                        'task_vars': task_vars,
                        'play_context': play_context