Instance migration fails with "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!"

Issue

When trying to migrate an instance the following error is shown in Nova logs:

2021-08-12 14:28:01.844 7 ERROR nova.virt.libvirt.driver [-] [instance: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx] Live Migration failure: operation failed: Failed to connect to remote libvirt URI qemu+ssh://nova_migration@compute-0:2022/system?keyfile=/etc/nova/migration/identity: Cannot recv data: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:abcdefghi12345678+12345678abcdefghi.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending RSA key in /etc/ssh/ssh_known_hosts:2
RSA host key for [compute-0]:2022 has changed and you have requested strict checking.
Host key verification failed.: Connection reset by peer: libvirt.libvirtError: operation failed: Failed to connect to remote libvirt URI qemu+ssh://nova_migration@compute-0:2022/system?keyfile=/etc/nova/migration/identity: Cannot recv data: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@