### Summary

Same issue reported here: https://github.com/ansible/ansible/issues/67266

Which was closed because it was "just a warning", but it is a bug because the warning occurs even when auto_silent is used. Just need to add an "if is_silent" check to this warning.

Ansible version: 2.9.11

### Issue Type

Bug Report

### Component Name

interpreter_discovery

### Ansible Version

```console
$ ansible --version
ansible 2.9.11
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.6/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.6.8 (default, Dec  5 2019, 15:45:45) [GCC 8.3.1 20191121 (Red Hat 8.3.1-5)]
```


### Configuration

```console
$ ansible-config dump --only-changed
```


### OS / Environment

RHEL 8.2, ESXi 6.7 and 7.0 

### Steps to Reproduce

Run setup against an ESXi host with auto_silent interpreter; see warning.

### Expected Results

No warning about interpreter failure when silent mode is active.

### Actual Results

```console
Warning about no python interpreter when silent mode is active.
```


### Code of Conduct

I agree to follow the Ansible Code of Conduct
if action._connection.has_pipelining:
            res = action._low_level_execute_command(found_interpreters[0], sudoable=False, in_data=platform_script)
        else:
            
            raise NotImplementedError('pipelining support required for extended interpreter discovery')
        platform_info = json.loads(res.get('stdout'))
        distro, version = _get_linux_distro(platform_info)
        if not distro or not version:
            raise NotImplementedError('unable to get Linux distribution/version info')
        version_map = platform_python_map.get(distro.lower().strip())
        if not version_map:
            raise NotImplementedError('unsupported Linux distribution: {0}'.format(distro))
        platform_interpreter = to_text(_version_fuzzy_match(version, version_map), errors='surrogate_or_strict')
        
        if is_auto_legacy:
            if platform_interpreter != u'/usr/bin/python' and u'/usr/bin/python' in found_interpreters:
                
                if not is_silent:
                    action._discovery_deprecation_warnings.append(dict(
                        msg=u"Distribution {0} {1} on host {2} should use {3}, but is using "
                            u"/usr/bin/python for backward compatibility with prior Ansible releases. "
                            u"A future Ansible release will default to using the discovered platform "
                            u"python for this host. See {4} for more information"
                            .format(distro, version, host, platform_interpreter,
                                    get_versioned_doclink('reference_appendices/interpreter_discovery.html')),
                        version='2.12'))
                return u'/usr/bin/python'
        if platform_interpreter not in found_interpreters:
            if platform_interpreter not in bootstrap_python_list: