### 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.
return [(p.data["package-name"], p.version) for p in ProvidersManager().providers.values()]
    def show(self, output: str, console: AirflowConsole | None = None) -> None:
        """Shows information about Airflow instance."""
        all_info = {
            "Apache Airflow": self._airflow_info,
            "System info": self._system_info,
            "Tools info": self._tools_info,
            "Paths info": self._paths_info,
            "Providers info": self._providers_info,
        }
        console = console or AirflowConsole(show_header=False)
        if output in ("table", "plain"):
            
            for key, info in all_info.items():
                console.print(f"\n[bold][green]{key}[/bold][/green]", highlight=False)
                console.print_as(data=[{"key": k, "value": v} for k, v in info], output=output)
        else:
            
            console.print_as(
                data=[{k.lower().replace(" ", "_"): dict(v)} for k, v in all_info.items()], output=output
            )
    def render_text(self, output: str) -> str:
        """Exports the info to string."""
        console = AirflowConsole(record=True)
        with console.capture():
            self.show(output=output, console=console)
        return console.export_text()
class FileIoException(Exception):