### Summary

when running ansible-test over a collection, if there are errors or failures, it will link you to the correct documentation to help resolve the issue. this functionality is currently broken as it is linking to `docs.ansible.com/ansible/` instead of `docs.ansible.com/ansible-core/` which leads to 404s. 


### Issue Type

Bug Report

### Component Name

ansible-test

### Ansible Version

```console
$ ansible --version
ansible [core 2.11.2]
```


### Configuration

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


### OS / Environment

Fedora 34

### Steps to Reproduce

<!--- Paste example playbooks or commands between quotes below -->
```yaml (paste below)
ansible-test sanity --docker
```


### Expected Results

Expect for docs link to correct navigate to the correct documentation. 

### Actual Results

```console
leads to documentation that 404s. Ex: https://docs.ansible.com/ansible/2.12/dev_guide/testing/sanity/pylint.html
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
with CaptureStd():
            try:
                existing_doc, dummy_examples, dummy_return, existing_metadata = get_docstring(
                    self.base_module, fragment_loader, verbose=True, collection_name=self.collection_name, is_module=True)
                existing_options = existing_doc.get('options', {}) or {}
            except AssertionError:
                fragment = doc['extends_documentation_fragment']
                self.reporter.warning(
                    path=self.object_path,
                    code='missing-existing-doc-fragment',
                    msg='Pre-existing DOCUMENTATION fragment missing: %s' % fragment
                )
                return
            except Exception as e:
                self.reporter.warning_trace(
                    path=self.object_path,
                    tracebk=e
                )
                self.reporter.warning(
                    path=self.object_path,
                    code='unknown-doc-fragment',
                    msg=('Unknown pre-existing DOCUMENTATION error, see TRACE. Submodule refs may need updated')
                )
                return
        try:
            mod_collection_name = existing_doc.get('version_added_collection')
            mod_version_added = self._create_strict_version(
                str(existing_doc.get('version_added', '0.0')),
                collection_name=mod_collection_name)
        except ValueError: