Bump ec2_test_instance::modernisation-platform-terraform-ec2-instance

Bumps [ec2_test_instance::modernisation-platform-terraform-ec2-instance](https://github.com/ministryofjustice/modernisation-platform-terraform-ec2-instance) from 2.2.0 to 2.3.1.
- [Release notes](https://github.com/ministryofjustice/modernisation-platform-terraform-ec2-instance/releases)
- [Commits](ministryofjustice/modernisation-platform-terraform-ec2-instance@v2.2.0...v2.3.1)

---
updated-dependencies:
- dependency-name: ec2_test_instance::github::ministryofjustice/modernisation-platform-terraform-ec2-instance::v2.2.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

terraform/environments/example/ec2.tf

@@ -4,7 +4,7 @@
 
 # EC2 Created via module
 module "ec2_test_instance" {
-  source = "github.com/ministryofjustice/modernisation-platform-terraform-ec2-instance?ref=v2.2.0"
+  source = "github.com/ministryofjustice/modernisation-platform-terraform-ec2-instance?ref=v2.3.1"
 
   providers = {
     aws.core-vpc = aws.core-vpc # core-vpc-(environment) holds the networking for all accounts