terraform: set empty default value for additional_tags (#3052)

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

terraform/infrastructure/aws/variables.tf

@@ -82,5 +82,6 @@ variable "enable_snp" {
 
 variable "additional_tags" {
   type        = map(any)
+  default     = {}
   description = "Additional tags that should be applied to created resources."
 }

terraform/infrastructure/azure/variables.tf

@@ -92,5 +92,6 @@ variable "marketplace_image" {
 
 variable "additional_tags" {
   type        = map(any)
+  default     = {}
   description = "Additional tags that should be applied to created resources."
 }

terraform/infrastructure/gcp/variables.tf

@@ -72,5 +72,6 @@ variable "cc_technology" {
 
 variable "additional_labels" {
   type        = map(any)
+  default     = {}
   description = "Additional labels that should be given to created recources."
 }

terraform/infrastructure/openstack/variables.tf

@@ -61,6 +61,7 @@ variable "floating_ip_pool_id" {
 
 variable "additional_tags" {
   type        = list(any)
+  default     = []
   description = "Additional tags that should be applied to created resources."
 }