refactor: remove unnecessary lookup for safer_cluster nodepool ID

Resolve tflint error on an unecessary `lookup()` call in safer_cluster
node pool IDs.

`each.key` should function properly here, since the name is the key for
each of the maps in the map of maps, though `each.value.name` should
work as well.

Author: wyardley

autogen/main/cluster.tf.tmpl

@@ -753,7 +753,7 @@ locals {
 resource "random_id" "name" {
   for_each    = merge(local.node_pools, local.windows_node_pools)
   byte_length = 2
-  prefix      = format("%s-", lookup(each.value, "name"))
+  prefix      = "${each.key}-"
   keepers = merge(
     zipmap(
       local.force_node_pool_recreation_resources,

modules/beta-private-cluster-update-variant/cluster.tf

@@ -647,7 +647,7 @@ locals {
 resource "random_id" "name" {
   for_each    = merge(local.node_pools, local.windows_node_pools)
   byte_length = 2
-  prefix      = format("%s-", lookup(each.value, "name"))
+  prefix      = "${each.key}-"
   keepers = merge(
     zipmap(
       local.force_node_pool_recreation_resources,

modules/beta-public-cluster-update-variant/cluster.tf

@@ -626,7 +626,7 @@ locals {
 resource "random_id" "name" {
   for_each    = merge(local.node_pools, local.windows_node_pools)
   byte_length = 2
-  prefix      = format("%s-", lookup(each.value, "name"))
+  prefix      = "${each.key}-"
   keepers = merge(
     zipmap(
       local.force_node_pool_recreation_resources,

modules/private-cluster-update-variant/cluster.tf

@@ -588,7 +588,7 @@ locals {
 resource "random_id" "name" {
   for_each    = merge(local.node_pools, local.windows_node_pools)
   byte_length = 2
-  prefix      = format("%s-", lookup(each.value, "name"))
+  prefix      = "${each.key}-"
   keepers = merge(
     zipmap(
       local.force_node_pool_recreation_resources,