[backport][v7] fix: GKE cluster update behavior

[matttrach]

Tracking:
Main issue: #1499
Master PR: #1518
Backport PR: #1524

[vivek-shilimkar]

Tested the bug fix on rancher v2.11-head with rancher2 provider v7.3.0-rc1
Manually changing the node count do not require recreation cluster, the new nodes gets added successfully. Since the issue is fixed it can be closed.