fixup! Migrate cluster modules from map(map(string)) to map(object)

Author: pst

google/_modules/gke/node_pool/variables.tf

@@ -138,6 +138,8 @@ variable "taints" {
     effect = string
   }))
   description = "Taints to configure for the node pool."
+  default     = []
+  nullable    = false
 }
 
 variable "instance_tags" {
@@ -187,4 +189,6 @@ variable "network_config" {
     pod_ipv4_cidr_block  = string
   })
   description = "Configure additional pod IP address range for the node pool. Defaults to `null`"
+  default     = null
+  nullable    = false
 }