### 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.
print("Checking for duplicates in list of {sensors, hooks, operators}")
    for (yaml_file_path, provider_data), resource_type in product(
        yaml_files.items(), ["sensors", "operators", "hooks"]
    ):
        resource_data = provider_data.get(resource_type, [])
        current_integrations = [r.get("integration-name", "") for r in resource_data]
        if len(current_integrations) != len(set(current_integrations)):
            for integration in current_integrations:
                if current_integrations.count(integration) > 1:
                    errors.append(
                        f"Duplicated content of '{resource_type}/integration-name/{integration}' "
                        f"in file: {yaml_file_path}"
                    )
def check_completeness_of_list_of_transfers(yaml_files: dict[str, dict]):