### Summary

Running `ansible-doc -l` generates 430 deprecation warnings on stderr before printing anything to stdout.
```
[DEPRECATION WARNING]: amazon.aws.aws_az_facts has been deprecated.
aws_az_facts was renamed in Ansible 2.9 to aws_az_info. Please update your
tasks. This feature will be removed from amazon.aws in a release after
2022-06-01. Deprecation warnings can be disabled by setting
deprecation_warnings=False in ansible.cfg.

[DEPRECATION WARNING]: amazon.aws.aws_caller_facts has been deprecated.
aws_caller_facts was renamed in Ansible 2.9 to aws_caller_info. Please update
your tasks. This feature will be removed from amazon.aws in a release after
2021-12-01. Deprecation warnings can be disabled by setting
deprecation_warnings=False in ansible.cfg.
...
```

### Issue Type

Bug Report

### Component Name

ansible-doc

### Ansible Version

```console
$ ansible-doc --version

ansible-doc 2.10.6
  config file = None
  configured module search path = [u'/home/charleshowes/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python2.7/dist-packages/ansible
  executable location = /usr/local/bin/ansible-doc
  python version = 2.7.17 (default, Sep 30 2020, 13:38:04) [GCC 7.5.0]
```


### Configuration

```console
$ ansible-config dump --only-changed
(no output)
```


### OS / Environment

Ubuntu 18.04

### Steps to Reproduce

<!--- Paste example playbooks or commands between quotes below -->
```shell (paste below)
ansible-doc -l
```


### Expected Results

I expected to see a list of available plugins, and was shocked to have pages and pages of warnings.

### Actual Results

```console
$ ansible-doc -l 2>&1 | head

[DEPRECATION WARNING]: amazon.aws.aws_az_facts has been deprecated. 
aws_az_facts was renamed in Ansible 2.9 to aws_az_info. Please update your 
tasks. This feature will be removed from amazon.aws in a release after 
2022-06-01. Deprecation warnings can be disabled by setting 
deprecation_warnings=False in ansible.cfg.
[DEPRECATION WARNING]: amazon.aws.aws_caller_facts has been deprecated. 
aws_caller_facts was renamed in Ansible 2.9 to aws_caller_info. Please update 
your tasks. This feature will be removed from amazon.aws in a release after 
2021-12-01. Deprecation warnings can be disabled by setting 
deprecation_warnings=False in ansible.cfg.

$ ansible-doc -l 2>&1 | grep -c 'DEPRECATION WARNING'

430
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
"""
        Differences with :meth:`PluginLoader.all`:
        * Unlike other plugin types, file != plugin, a file can contain multiple plugins (of same type).
          This is why we do not deduplicate ansible file names at this point, we mostly care about
          the names of the actual jinja2 plugins which are inside of our files.
        * We reverse the order of the list of files compared to other PluginLoaders.  This is
          because of how calling code chooses to sync the plugins from the list.  It adds all the
          Jinja2 plugins from one of our Ansible files into a dict.  Then it adds the Jinja2
          plugins from the next Ansible file, overwriting any Jinja2 plugins that had the same
          name.  This is an encapsulation violation (the PluginLoader should not know about what
          calling code does with the data) but we're pushing the common code here.  We'll fix
          this in the future by moving more of the common code into this PluginLoader.
        * We return a list.  We could iterate the list instead but that's extra work for no gain because
          the API receiving this doesn't care.  It just needs an iterable
        * This method will NOT fetch collection plugins, only those that would be expected under 'ansible.legacy'.
        """
        
        
        kwargs['_dedupe'] = False
        
        
        
        
        
        
        
        files = list(super(Jinja2Loader, self).all(*args, **kwargs))
        files .reverse()
        return files
def _load_plugin_filter():