What type of PR is this?

/kind bug

What this PR does / why we need it:

Fixes optimistic lock conflicts (409 Conflict errors) when replaying topology labels to nodes after they become unavailable and are replaced during e2e testing.

Problem:

• reapplyNodeLabels() in operator/e2e/setup/k8s_clusters.go used full Update() call
• Between fetching node and updating labels, ResourceVersion can change (kubelet, node controller)
• Results in 409 Conflict errors due to stale ResourceVersion

Solution:

• Switch from Update() to Patch() with StrategicMergePatchType
• Patch operations apply regardless of ResourceVersion
• Only modifies topology labels field, doesn't touch other node fields
• Follows existing pattern from applyTopologyLabels()

Impact:

• Eliminates optimistic lock conflicts during topology label replay
• More efficient (only sends label changes)
• Safer (doesn't risk overwriting concurrent changes)

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

• Changes only affect e2e test infrastructure
• Follows existing pattern from applyTopologyLabels() in setup/topology.go
• No functional behavior change - same topology labels applied, different mechanism
• Strategic merge patch automatically handles label merging

Does this PR introduce a API change?

NONE

Additional documentation e.g., enhancement proposals, usage docs, etc.:

NONE