terraform tests: Set default replication factors

Follow-up to #31452

Seen failing in https://buildkite.com/materialize/nightly/builds/11143#019501e1-d68b-407e-8801-4a60b5a18f5d

Author: def-

test/terraform/aws-persistent/main.tf

@@ -24,6 +24,15 @@ module "materialize_infrastructure" {
   environment  = "dev"
   install_materialize_operator = true
 
+  helm_values = {
+      defaultReplicationFactor = {
+          system = 1
+          probe = 1
+          support = 1
+          analytics = 1
+      }
+  }
+
   # VPC Configuration
   vpc_cidr             = "10.0.0.0/16"
   availability_zones   = ["us-east-1a", "us-east-1b"]

test/terraform/aws-temporary/main.tf

@@ -26,6 +26,15 @@ module "materialize_infrastructure" {
   environment  = "dev"
   install_materialize_operator = true
 
+  helm_values = {
+      defaultReplicationFactor = {
+          system = 1
+          probe = 1
+          support = 1
+          analytics = 1
+      }
+  }
+
   # VPC Configuration
   vpc_cidr             = "10.0.0.0/16"
   availability_zones   = ["us-east-1a", "us-east-1b"]

test/terraform/gcp-temporary/main.tf

@@ -42,6 +42,15 @@ module "materialize" {
   }
 
   install_materialize_operator = true
+
+  helm_values = {
+      defaultReplicationFactor = {
+          system = 1
+          probe = 1
+          support = 1
+          analytics = 1
+      }
+  }
 }
 
 variable "project_id" {