Description of problem:

For an provisioned host when trying to set the host to build mode fails with Error `Request failed with status code 500`  

How reproducible:

100%

Is this issue a regression from an earlier version:

Yes

Steps to Reproduce:

1. Provision a host

2. After the host is provisioned successfully, try to set the host to Build mode

Actual behavior:
When trying to set the provisioned host to build mode, it fails with error `Request failed with status code 500`  

Expected behavior:
Should be able to put the host into build mode

Business Impact / Additional info:

As a workaround, Removing the lease entry from the /var/lib/dhcpd/dhcpd.leases file and restarting the dhcpd service works.

Logs:

2025-04-09T13:45:33 [W|app|d663f969] Rolling back due to a problem: [#<Orchestration::Task:0x00007f6da9e8ece8 @name="Create DHCP Settings for terri-lurie.sganar.com", @id="dhcp_create_00:50:56:bc:f0:71", @status="failed", @priority=9, @action=[#<Nic::Managed id: 10, mac: "00:50:56:bc:f0:71", ip: "10.0.39.84", type: "Nic::Managed", name: "terri-lurie.sganar.com", host_id: 9, subnet_id: 1, domain_id: 2, attrs: {}, created_at: "2025-04-09 23:02:02.184486000 +0530", updated_at: "2025-04-09 23:08:10.494878000 +0530", provider: nil, username: nil, password: nil, virtual: false, link: true, identifier: "ens32", tag: "", attached_to: "", managed: true, mode: "balance-rr", attached_devices: "", bond_options: "", primary: true, provision: true, compute_attributes:

, execution: true, ip6: nil, subnet6_id: nil>, :set_dhcp], @created=1744220733.1155527, @timestamp=2025-04-09 17:45:33.40726026 UTC>]
2025-04-09T13:45:33 [I|app|d663f969] Create DHCP reservation terri-lurie.sganar.com for terri-lurie.sganar.com-00:50:56:bc:f0:71/10.0.39.84
2025-04-09T13:45:33 [W|app|d663f969] Failed to perform rollback on Remove DHCP Settings for terri-lurie.sganar.com - ERF12-6899 [ProxyAPI::ProxyException]: Unable to set DHCP entry ([RestClient::Conflict]: 409 Conflict) for Capsule https://ip-10-0-221-227.rhos-01.prod.psi.rdu2.redhat.com:9090/dhcp
2025-04-09T13:45:33 [I|app|d663f969] Backtrace for 'Failed to perform rollback on Remove DHCP Settings for terri-lurie.sganar.com - ERF12-6899 [ProxyAPI::ProxyException]: Unable to set DHCP entry ([RestClient::Conflict]: 409 Conflict) for Capsule https://ip-10-0-221-227.rhos-01.prod.psi.rdu2.redhat.com:9090/dhcp' error (ProxyAPI::ProxyException): ERF12-6899 [ProxyAPI::ProxyException]: Unable to set DHCP entry ([RestClient::Conflict]: 409 Conflict) for Capsule https://ip-10-0-221-227.rhos-01.prod.psi.rdu2.redhat.com:9090/dhcp
 d663f969 | /usr/share/foreman/app/services/proxy_api/dhcp.rb:89:in `rescue in set'
.
.
.

2025-04-09T13:45:33 [E|app|d663f969] Task 'Fetch TFTP boot files for terri-lurie.sganar.com' canceled
2025-04-09T13:45:33 [E|app|d663f969] Task 'Mark Content Host Statuses as Unknown for terri-lurie.sganar.com' canceled
2025-04-09T13:45:33 [W|app|d663f969] Set build failed: #<ActiveModel::Errors [#<ActiveModel::Error attribute=base, type=Create DHCP Settings for terri-lurie.sganar.com task failed with the following error: ERF12-6899 [ProxyAPI::ProxyException]: Unable to set DHCP entry ([RestClient::Conflict]: 409 Conflict) for Capsule https://ip-10-0-221-227.rhos-01.prod.psi.rdu2.redhat.com:9090/dhcp, options={}>, #<ActiveModel::Error attribute=base, type=Failed to perform rollback on Remove DHCP Settings for terri-lurie.sganar.com - ERF12-6899 [ProxyAPI::ProxyException]: Unable to set DHCP entry ([RestClient::Conflict]: 409 Conflict) for Capsule https://ip-10-0-221-227.rhos-01.prod.psi.rdu2.redhat.com:9090/dhcp, options={}>]>
2025-04-09T13:45:33 [I|app|d663f969] Completed 500 Internal Server Error in 789ms (Views: 0.2ms | ActiveRecord: 19.3ms | Allocations: 94695)