changing host fingerprints requires manual approval

[sjpb]

e.g.

TASK [common : Ensure hosts are in SSH known hosts] **********************************************************************************************************************************************************************
changed: [lustre-lnet2 -> localhost]
changed: [lustre-client1 -> localhost]
changed: [lustre-client3 -> localhost]
changed: [lustre-client2 -> localhost]
ok: [lustre-admin -> localhost]
changed: [lustre-storage -> localhost]
changed: [lustre-lnet3 -> localhost]

TASK [common : install rng-tools] ****************************************************************************************************************************************************************************************
The authenticity of host '192.168.43.12 (<no hostip for proxy command>)' can't be established.
ECDSA key fingerprint is SHA256:BcwI2I9ime4Kmt2E3G9Z45LOGiOzsgY9AKJ8huj4sAk.
ECDSA key fingerprint is MD5:c0:0f:37:ff:0f:e4:90:5e:09:57:9a:b8:35:36:a4:a7.
Are you sure you want to continue connecting (yes/no)? yes
ok: [lustre-admin]
ok: [lustre-storage]
changed: [lustre-client2]
The authenticity of host '192.168.42.6 (<no hostip for proxy command>)' can't be established.
ECDSA key fingerprint is SHA256:CWZebApJigp3buAjOKFMOgcwkj8S+mgs25vfIxkNfKI.
ECDSA key fingerprint is MD5:e6:c2:e2:7e:d8:92:05:24:dd:1a:00:56:31:ca:cc:2b.
Are you sure you want to continue connecting (yes/no)? yes

This is despite the ssh task which is supposed to add keys - current guess is that because of the connection pipelining, having the ssh and rng-tools tasks in the same play means that known_hosts does not get re-read after adding them.