### Body

We had an issue where extra link class (`AIPlatformConsoleLink`) was removed in [PR](https://github.com/apache/airflow/pull/26836) without removing the class from the `provider.yaml` extra links this resulted in web server exception as shown in https://github.com/apache/airflow/pull/28449


**The Task:**
Add validation that classes of extra-links in provider.yaml are importable

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
)
if __name__ == "__main__":
    provider_files_pattern = pathlib.Path(ROOT_DIR).glob("airflow/providers/**/provider.yaml")
    all_provider_files = sorted(str(path) for path in provider_files_pattern)
    if len(sys.argv) > 1:
        paths = sorted(sys.argv[1:])
    else:
        paths = all_provider_files
    all_parsed_yaml_files: dict[str, dict] = _load_package_data(paths)
    all_files_loaded = len(all_provider_files) == len(paths)
    check_integration_duplicates(all_parsed_yaml_files)
    check_completeness_of_list_of_hooks_sensors_hooks(all_parsed_yaml_files)
    check_duplicates_in_integrations_names_of_hooks_sensors_operators(all_parsed_yaml_files)
    check_completeness_of_list_of_transfers(all_parsed_yaml_files)
    check_duplicates_in_list_of_transfers(all_parsed_yaml_files)
    check_hook_classes(all_parsed_yaml_files)
    check_unique_provider_name(all_parsed_yaml_files)
    check_providers_are_mentioned_in_issue_template(all_parsed_yaml_files)
    check_providers_have_all_documentation_files(all_parsed_yaml_files)
    if all_files_loaded:
        
        check_doc_files(all_parsed_yaml_files)
        check_invalid_integration(all_parsed_yaml_files)
    if errors:
        console = Console(width=400, color_system="standard")
        console.print(f"[red]Found {len(errors)} errors in providers[/]")
        for error in errors:
            console.print(f"[red]Error:[/] {error}")
        sys.exit(1)