fix: remove unsupported affinity param from HA rule test

PVE 9 rejects 'affinity' as an unexpected property on POST
cluster/ha/rules — it's implied by the node-affinity type.

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

tests/PSProxmoxVE.Tests/Integration/ZZ.ClusterConfig.Integration.Tests.ps1

@@ -422,7 +422,6 @@ Describe 'Cluster Config & HA Lifecycle — Integration' -Tag 'Integration' {
                     rule      = 'pester-rule-1'
                     resources = 'vm:99999'
                     nodes     = $script:Node
-                    affinity  = 'positive'
                 } `
                 -Comment 'Pester test rule' `
                 -Confirm:$false `