fix: Correct eks_managed_* to self_managed_* for tag_specification argument (terraform-aws-modules#2364)

Fix incorrect variable name on self managed nodes

Self managed nodes were pulling from the eks_managed_node_group_defaults and not self_managed_node_group_defaults for tag_specifications.

Author: lordspacehog

node_groups.tf

@@ -423,7 +423,7 @@ module "self_managed_node_group" {
   update_launch_template_default_version = try(each.value.update_launch_template_default_version, var.self_managed_node_group_defaults.update_launch_template_default_version, true)
   launch_template_description            = try(each.value.launch_template_description, var.self_managed_node_group_defaults.launch_template_description, "Custom launch template for ${try(each.value.name, each.key)} self managed node group")
   launch_template_tags                   = try(each.value.launch_template_tags, var.self_managed_node_group_defaults.launch_template_tags, {})
-  tag_specifications                     = try(each.value.tag_specifications, var.eks_managed_node_group_defaults.tag_specifications, ["instance", "volume", "network-interface", "spot-instances-request"])
+  tag_specifications                     = try(each.value.tag_specifications, var.self_managed_node_group_defaults.tag_specifications, ["instance", "volume", "network-interface", "spot-instances-request"])
 
   ebs_optimized   = try(each.value.ebs_optimized, var.self_managed_node_group_defaults.ebs_optimized, null)
   ami_id          = try(each.value.ami_id, var.self_managed_node_group_defaults.ami_id, "")