### 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.
"""Upload text file to File.io service and return link."""
    resp = httpx.post("https://file.io", content=content)
    if resp.status_code not in [200, 201]:
        print(resp.json())
        raise FileIoException("Failed to send report to file.io service.")
    try:
        return resp.json()["link"]
    except ValueError as e:
        log.debug(e)
        raise FileIoException("Failed to send report to file.io service.")
def _send_report_to_fileio(info):
    print("Uploading report to file.io service.")
    try:
        link = _upload_text_to_fileio(str(info))
        print("Report uploaded.")
        print(link)
        print()
    except FileIoException as ex:
        print(str(ex))
@suppress_logs_and_warning
def show_info(args):
    """Show information related to Airflow, system and other."""
    
    anonymizer = PiiAnonymizer() if args.anonymize or args.file_io else NullAnonymizer()
    info = AirflowInfo(anonymizer)
    if args.file_io:
        _send_report_to_fileio(info.render_text(args.output))
    else:
        info.show(args.output)