### Summary

Since dnf is not installing the packages when running `dnf download --downloadonly...`, it does not require root access to pull down the rpms. It would be nice if ansible followed the same pattern.

### Issue Type

Feature Idea

### Component Name

dnf

### Additional Information

<!--- Paste example playbooks or commands between quotes below -->
```yaml (paste below)
    - name: Download RPM's
      dnf:
        name: "{{ item }}"
        state: present
        download_only: yes
        download_dir: "{{ rpms_path }}"
      loop: "{{ rpms }}"
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
- Disable the excludes defined in DNF config files.
      - If set to C(all), disables all excludes.
      - If set to C(main), disable excludes defined in [main] in dnf.conf.
      - If set to C(repoid), disable excludes defined for given repo id.
    version_added: "2.7"
    type: str
  validate_certs:
    description:
      - This only applies if using a https url as the source of the rpm. e.g. for localinstall. If set to C(no), the SSL certificates will not be validated.
      - This should only set to C(no) used on personally controlled sites using self-signed certificates as it avoids verifying the source site.
    type: bool
    default: "yes"
    version_added: "2.7"
  allow_downgrade:
    description:
      - Specify if the named package and version is allowed to downgrade
        a maybe already installed higher version of that package.
        Note that setting allow_downgrade=True can make this module
        behave in a non-idempotent way. The task could end up with a set
        of packages that does not match the complete list of specified
        packages to install (because dependencies between the downgraded
        package and others can cause changes to the packages which were
        in the earlier transaction).
    type: bool
    default: "no"
    version_added: "2.7"
  install_repoquery:
    description:
      - This is effectively a no-op in DNF as it is not needed with DNF, but is an accepted parameter for feature
        parity/compatibility with the I(yum) module.