Ensure `ServerPowerState: Off` after Maintenance

[defo89]

Describe the bug
Currently it is desired for the Server to be inspected after maintenance (in case of hardware changes).

Maintenance -> Initial -> Discovery

Following issue is observed:

• Server power is Off, status Maintenance
• Maintenance completed, status Initial
• During this time before reconciliation happens, Server is powered On
• Server boots up, rejoins the cluster, is Ready and has new pods scheduled
• Server is reconciled and powered Off for Discovery/PXE boot to start metalprobe

We should ensure that server is not powered on after Maintenance to avoid issues with the payload.

› kg biosversion dell-poweredge-r640-2-22-2-server1-system-0
dell-poweredge-r640-2-22-2-server1system-0   2.22.2                      server1-system-0   dell-poweredge-r640-2-22-2-server1-system-0   Starting    OK                          Processing   8d
dell-poweredge-r640-2-22-2-server1-system-0   2.22.2                      server1-system-0   dell-poweredge-r640-2-22-2-server1-system-0   Running     OK           10             Processing   8d

While we get the update about successful completion, Server is powered on:

› kg server server1-system-0 -w
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   Off          Maintenance   74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   On           Maintenance   74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   On           Maintenance   74d <<<<<<<<
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   On           Initial       74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   On           Initial       74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   On           Initial       74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   Off          Initial       74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   Off          Initial       74d
server1-system-0   4c4c4544-004c-3510-8051-c3c04f565033   Dell Inc.      PowerEdge R640   Off          Discovery     74d

› kg biosversion dell-poweredge-r640-2-22-2-server1-system-0 -w
dell-poweredge-r640-2-22-2-server1-system-0   2.22.2                      server1-system-0   dell-poweredge-r640-2-22-2-server1-system-0   Completed   OK           100            Processing   8d

[Nuckal777]

On quick glance the Server controller and ServerClaim both patch the power state in the Initial and Discovery state. The ServerClaim reconciler only skips reconciliation for bound claims, if it's server in in Maintenance.

[Nuckal777]

Apparently, some BIOS updates trigger a reboot automatically after applying. Let's evaluate redfishs BootSourceOverrideTarget to force a boot into nothing.