Hello Ghalied Majiet,
Thanks for your question.
Any unused connectors/agents are tagged as inactive and are removed automatically after 10 days of inactivity.
So, you may not need any action from your end. This is cited from: https://learn.microsoft.com/en-us/answers/questions/1310381/unable-to-remove-old-azure-cloud-agent-from-aad-po
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola