### Summary

The [`filename` parameter docs](https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_repository_module.html#parameter-filename) don't give enough info to tell how the file name is generated.

I believe my `repo: deb https://packagecloud.io/linz/prod/ubuntu/ {{ ansible_distribution_release }} main` is hanging indefinitely ~~, and I suspect this has something to do with the file name being a duplicate, resulting in a background prompt which is never printed or dismissed, but it's hard to tell based on the [code](https://github.com/ansible/ansible/blob/f3be331c9cb2f2c6edeb0bdf28a1e8a9681d727c/lib/ansible/modules/apt_repository.py#L235-L258)~~ (Based on copying the code into a Python interpreter it looks like the generated file name is `packagecloud_io_linz_prod_ubuntu.list`, which looks fine.).

### Issue Type

Documentation Report

### Component Name

lib/ansible/modules/apt_repository.py

### Ansible Version

```console
N/A
```


### Configuration

```console
N/A
```


### OS / Environment

N/A

### Additional Information

N/A

### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
return UbuntuSourcesList(self.module)
    def _get_ppa_info(self, owner_name, ppa_name):
        lp_api = self.LP_API % (owner_name, ppa_name)
        headers = dict(Accept='application/json')
        response, info = fetch_url(self.module, lp_api, headers=headers)
        if info['status'] != 200:
            self.module.fail_json(msg="failed to fetch PPA information, error was: %s" % info['msg'])
        return json.loads(to_native(response.read()))
    def _expand_ppa(self, path):
        ppa = path.split(':')[1]
        ppa_owner = ppa.split('/')[0]
        try:
            ppa_name = ppa.split('/')[1]
        except IndexError:
            ppa_name = 'ppa'
        line = 'deb http://ppa.launchpad.net/%s/%s/ubuntu %s main' % (ppa_owner, ppa_name, self.codename)
        return line, ppa_owner, ppa_name
    def _key_already_exists(self, key_fingerprint):
        if self.apt_key_bin:
            rc, out, err = self.module.run_command([self.apt_key_bin, 'export', key_fingerprint], check_rc=True)
            found = len(err) == 0
        else:
            found = self._gpg_key_exists(key_fingerprint)
        return found
    def _gpg_key_exists(self, key_fingerprint):