fix: Add missing private subnets to max subnet length local (#920)

Author: bryantbiggs

examples/simple/main.tf

@@ -29,10 +29,7 @@ module "vpc" {
   cidr = local.vpc_cidr
 
   azs             = local.azs
-  private_subnets = [for k, v in local.azs : cidrsubnet(local.vpc_cidr, 8, k)]
-  public_subnets  = [for k, v in local.azs : cidrsubnet(local.vpc_cidr, 8, k + 4)]
-
-  enable_nat_gateway = false
+  private_subnets = [for k, v in local.azs : cidrsubnet(local.vpc_cidr, 4, k)]
 
   tags = local.tags
 }

main.tf

@@ -8,7 +8,9 @@ locals {
   len_outpost_subnets     = max(length(var.outpost_subnets), length(var.outpost_subnet_ipv6_prefixes))
 
   max_subnet_length = max(
+    local.len_private_subnets,
     local.len_public_subnets,
+    local.len_intra_subnets,
     local.len_elasticache_subnets,
     local.len_database_subnets,
     local.len_redshift_subnets,