How to unlink the previous SSH key in Git

Question

I have followed the following steps to create and add a SSH key and deleted all the previously created keys in the folder ~/.ssh/

• $ ssh-keygen -t rsa -b 4096 -C "[email protected]"
• $ eval "$(ssh-agent -s)"
• $ ssh-add -K ~/.ssh/id_rsa
• $ clip < ~/.ssh/id_rsa.pub and then added the content in Git

Then I try:

• $ git push -u origin master

and I get:

The authenticity of host 'github.com (140.82.121.4)' can't be established. ED25519 key fingerprint is SHA256:+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU. This key is not known by any other names. Are you sure you want to continue connecting (yes/no/[fingerprint])?

(That key is one of the previous I had created and deleted)

What can I do to overcome this issue?