fix(test): add missing Url and Key params to New-PveSdnDns no-session test

New-PveSdnDns requires mandatory Url and Key parameters. The no-session
test was failing with "missing mandatory parameters" instead of reaching
the session check.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/PSProxmoxVE.Tests/Network/SdnIpamDnsControllerCmdlets.Tests.ps1

@@ -275,7 +275,7 @@ Describe 'New-PveSdnDns' {
     Context 'Without active session' {
         It 'Should throw when no session is active' {
             Skip-IfMissing 'New-PveSdnDns'
-            { New-PveSdnDns -Dns 'testdns' -Type 'powerdns' -ErrorAction Stop } |
+            { New-PveSdnDns -Dns 'testdns' -Type 'powerdns' -Url 'http://localhost:8081' -Key 'testkey' -ErrorAction Stop } |
                 Should -Throw '*No active Proxmox VE session*'
         }
     }