chore(deps): update terraform terraform-ibm-modules/event-notifications/ibm to v1.18.6 (#253)

Author: terraform-ibm-modules-ops

tests/resources/existing-resources/instances/main.tf

@@ -46,7 +46,7 @@ module "cloud_monitoring" {
 
 module "event_notifications" {
   source            = "terraform-ibm-modules/event-notifications/ibm"
-  version           = "1.18.5"
+  version           = "1.18.6"
   resource_group_id = module.resource_group.resource_group_id
   name              = "${var.prefix}-en"
   tags              = var.resource_tags