Bug 2235037

Description of problem:
Upgraded director node on version 17.1 from 17.0 will not connect to overcloud nodes using the `id_rsa.pub` and `id_rsa_tripleo.pub` keys

https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/17.1/html-single/performing_a_minor_update_of_red_hat_openstack_platform/index#assembly_updating-the-overcloud_keeping-updated


Version-Release number of selected component (if applicable):
Red Hat OpenStack Platform release 17.1.0 (Wallaby)

How reproducible:
Upgrade director node to 17.1 from 17.0 and try to ssh to a overcloud node using the aforementioned keys


Steps to Reproduce:
1.Upgrade to 17.1 from 17.0 
2. ssh to one of the overcloud nodes. 
3.

Actual results:

```
(undercloud) [stack@director ~]$ ssh heat-admin.99.45                                                                                                                                                                             
load pubkey "/home/stack/.ssh/id_rsa": Invalid key length   
```

And during the update of the overcloud nodes at the first upgrade command that connects to the overcloud nodes 
  `openstack overcloud external-update run --stack <stack_name> --tags ovn`
```
PLAY [External update step 1] **************************************************                                                                                                                                                        	 
2023-08-26 14:11:37.826774 | 525400e9-eec8-171a-58c9-00000000012e |   	TASK | Force pull image in case image name doesn't change.                                                                                                    	 
2023-08-26 14:11:41.998325 | 525400e9-eec8-171a-58c9-00000000012e |  	FATAL | Force pull image in case image name doesn't change. | undercloud | item=overcloud-compute-0 | error={"ansible_loop_var": "item", "item": "overcloud-compute-
0", "msg": "Failed to connect to the host via ssh: load pubkey \"/home/stack/.ssh/id_rsa\": Invalid key length\r\nWarning: Permanently added '192.168.99.21' (ED25519) to the list of known hosts.\r\ntripleo-admin.99.21: Permission
 denied (publickey,password).", "unreachable": true}                                                                                                                                                                                    	 
2023-08-26 14:11:41.999642 | 525400e9-eec8-171a-58c9-00000000012e | 	TIMING | Force pull image in case image name doesn't change. | undercloud | 0:00:08.893209 | 4.17s                                                              	 
2023-08-26 14:11:46.136730 | 525400e9-eec8-171a-58c9-00000000012e |  	FATAL | Force pull image in case image name doesn't change. | undercloud | item=overcloud-compute-1 | error={"ansible_loop_var": "item", "item": "overcloud-compute-
1", "msg": "Failed to connect to the host via ssh: load pubkey \"/home/stack/.ssh/id_rsa\": Invalid key length\r\nWarning: Permanently added '192.168.99.38' (ED25519) to the list of known hosts.\r\ntripleo-admin.99.38: Permission
 denied (publickey,password).", "unreachable": true}                                                                                                                                                                                    	 
2023-08-26 14:11:46.137402 | 525400e9-eec8-171a-58c9-00000000012e | 	TIMING | Force pull image in case image name doesn't change. | undercloud | 0:00:13.030985 | 8.31s                                                              	 
2023-08-26 14:11:50.379641 | 525400e9-eec8-171a-58c9-00000000012e |  	FATAL | Force pull image in case image name doesn't change. | undercloud | item=overcloud-controller-0 | error={"ansible_loop_var": "item", "item": "overcloud-contr
oller-0", "msg": "Failed to connect to the host via ssh: load pubkey \"/home/stack/.ssh/id_rsa\": Invalid key length\r\nWarning: Permanently added '192.168.99.45' (ED25519) to the list of known hosts.\r\ntripleo-admin.99.45: Perm
ission denied (publickey,password).", "unreachable": true}                                                                                                                                                                              	 
2023-08-26 14:11:50.380326 | 525400e9-eec8-171a-58c9-00000000012e | 	TIMING | Force pull image in case image name doesn't change. | undercloud | 0:00:17.273909 | 12.55s                                                             	 
2023-08-26 14:11:54.567310 | 525400e9-eec8-171a-58c9-00000000012e |  	FATAL | Force pull image in case image name doesn't change. | undercloud | item=overcloud-controller-1 | error={"ansible_loop_var": "item", "item": "overcloud-contr
oller-1", "msg": "Failed to connect to the host via ssh: load pubkey \"/home/stack/.ssh/id_rsa\": Invalid key length\r\nWarning: Permanently added '192.168.99.55' (ED25519) to the list of known hosts.\r\ntripleo-admin.99.55: Perm
ission denied (publickey,password).", "unreachable": true}                                                                                                                                                                              	 
2023-08-26 14:11:54.567814 | 525400e9-eec8-171a-58c9-00000000012e | 	TIMING | Force pull image in case image name doesn't change. | undercloud | 0:00:21.461398 | 16.74s                                                             	 
2023-08-26 14:11:58.735350 | 525400e9-eec8-171a-58c9-00000000012e |  	FATAL | Force pull image in case image name doesn't change. | undercloud | item=overcloud-controller-2 | error={"ansible_loop_var": "item", "item": "overcloud-contr
oller-2", "msg": "Failed to connect to the host via ssh: load pubkey \"/home/stack/.ssh/id_rsa\": Invalid key length\r\nWarning: Permanently added '192.168.99.40' (ED25519) to the list of known hosts.\r\ntripleo-admin.99.40: Perm
ission denied (publickey,password).", "unreachable": true
```

Expected results:


Additional info:

A workaround to this issue would be below to get the upgrade completed. 
  https://access.redhat.com/solutions/6973518