ssh_genkeytypes in cloud-init config on the centos8 image we are using don't have proper values set.

The latest changes in cloud-init expect, cloud-init to create keys.

https://src.fedoraproject.org/rpms/cloud-init/c/b954b98a1c25b8db753dcd4545e2a72bbd0a2790

~~~
undercloud) [zuul@undercloud ~]$ wget https://images.rdoproject.org/CentOS-8-Stream-x86_64-GenericCloud.qcow2
--2022-05-06 03:09:09--  https://images.rdoproject.org/CentOS-8-Stream-x86_64-GenericCloud.qcow2
Resolving images.rdoproject.org (images.rdoproject.org)... 38.102.83.152
Connecting to images.rdoproject.org (images.rdoproject.org)|38.102.83.152|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1343368704 (1.3G)
Saving to: ‘CentOS-8-Stream-x86_64-GenericCloud.qcow2’

CentOS-8-Stream-x86_64-GenericCloud.qcow2                   100%[========================================================================================================================================>]   1.25G  20.9MB/s    in 37s     

2022-05-06 03:09:46 (35.1 MB/s) - ‘CentOS-8-Stream-x86_64-GenericCloud.qcow2’ saved [1343368704/1343368704]

(undercloud) [zuul@undercloud ~]$ guestfish -a CentOS-8-Stream-x86_64-GenericCloud.qcow2 

Welcome to guestfish, the guest filesystem shell for
editing virtual machine filesystems and disk images.

Type: ‘help’ for help on commands
      ‘man’ to read the manual
      ‘quit’ to quit the shell

><fs> mount /dev/sda1 /
><fs> cat /etc/cloud/cloud.cfg
users:
 - default

disable_root: 1
ssh_pwauth:   0

mount_default_fields: [~, ~, 'auto', 'defaults,nofail,x-systemd.requires=cloud-init.service', '0', '2']
resize_rootfs_tmp: /dev
ssh_deletekeys:   1

~~~~


vs new image

~~~
(undercloud) [zuul@undercloud ~]$ wget https://cloud.centos.org/centos/8-stream/x86_64/images/CentOS-Stream-GenericCloud-8-20220125.1.x86_64.qcow2
--2022-05-06 03:15:22--  https://cloud.centos.org/centos/8-stream/x86_64/images/CentOS-Stream-GenericCloud-8-20220125.1.x86_64.qcow2
Resolving cloud.centos.org (cloud.centos.org)... 3.137.219.52, 2600:1f16:c1:5e02:ec1b:2c09:2525:64e0
Connecting to cloud.centos.org (cloud.centos.org)|3.137.219.52|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1490685440 (1.4G) [application/octet-stream]
Saving to: ‘CentOS-Stream-GenericCloud-8-20220125.1.x86_64.qcow2’

CentOS-Stream-GenericCloud-8-20220125.1.x86_64.qcow2        100%[========================================================================================================================================>]   1.39G  53.2MB/s    in 18s     

2022-05-06 03:15:40 (78.2 MB/s) - ‘CentOS-Stream-GenericCloud-8-20220125.1.x86_64.qcow2’ saved [1490685440/1490685440]

(undercloud) [zuul@undercloud ~]$ guestfish -a CentOS-Stream-GenericCloud-8-20220125.1.x86_64.qcow2 

Welcome to guestfish, the guest filesystem shell for
editing virtual machine filesystems and disk images.

Type: ‘help’ for help on commands
      ‘man’ to read the manual
      ‘quit’ to quit the shell

><fs> run
><fs> list-filesystems
/dev/sda1: xfs
><fs> mount /dev/sda1 /
><fs> cat /etc/cloud/cloud.cfg
users:
 - default

disable_root: 1
ssh_pwauth:   0

mount_default_fields: [~, ~, 'auto', 'defaults,nofail,x-systemd.requires=cloud-init.service', '0', '2']
resize_rootfs_tmp: /dev
ssh_deletekeys:   1
ssh_genkeytypes:  ['rsa', 'ecdsa', 'ed25519']
~~~