BAU: Update terraform and providers to latest

Author: cadmiumcat

.github/workflows/terraform.yml

@@ -6,18 +6,21 @@ on:
       - ".review_apps/**"
   merge_group:
     types: [checks_requested]
-env:
-  TERRAFORM_VERSION: "1.11.0"
 jobs:
   terraform:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@71cf2267d89c5cb81562390fa70a37fa40b1305e # v5.0.0
 
+      - name: Determine Terraform version
+        id: terraform-version
+        run: |
+          cat .review_apps/.terraform-version | xargs printf "TF_VERSION=%s" >> "$GITHUB_OUTPUT"
+
       - uses: hashicorp/setup-terraform@b9cd54a3c349d3f38e8881555d616ced269862dd # v3.1.2
         with:
-          terraform_version: ${{env.TERRAFORM_VERSION}}
+          terraform_version: ${{steps.terraform-version.outputs.TF_VERSION}}
 
       - name: Check Terraform style
         id: tf_fmt
@@ -32,6 +35,6 @@ jobs:
 
       - name: Validate Terraform syntax
         working-directory: ".review_apps/"
-        run : |
+        run: |
           terraform init -backend=false || exit
           terraform validate

.review_apps/.gitignore

@@ -0,0 +1,2 @@
+# When testing, it's useful to create `terraform.tfvars`. But we shouldn't ever commit it.
+terraform.tfvars

.review_apps/.terraform-version

@@ -1 +1 @@
-1.11.0
+1.13.5

.review_apps/.terraform.lock.hcl

@@ -1,15 +1,15 @@
 terraform {
-  required_version = "~> 1.11.0"
+  required_version = "~> 1.13.5"
 
   required_providers {
     aws = {
       source  = "hashicorp/aws"
-      version = "~> 5.72.1"
+      version = "~> 6.20.0"
     }
 
     time = {
       source  = "hashicorp/time"
-      version = "0.11.1"
+      version = "0.13.1"
     }
   }