terraform(deps): bump terraform-aws-modules/rds/aws

Bumps [terraform-aws-modules/rds/aws](https://github.com/terraform-aws-modules/terraform-aws-rds) from 6.3.1 to 6.4.0.
- [Release notes](https://github.com/terraform-aws-modules/terraform-aws-rds/releases)
- [Changelog](https://github.com/terraform-aws-modules/terraform-aws-rds/blob/master/CHANGELOG.md)
- [Commits](terraform-aws-modules/terraform-aws-rds@v6.3.1...v6.4.0)

---
updated-dependencies:
- dependency-name: terraform-aws-modules/rds/aws
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

terraform/aws/analytical-platform-production/cluster/rds.tf

@@ -6,7 +6,7 @@ module "rds" {
   #checkov:skip=CKV_TF_1:Module registry does not support commit hashes for versions
 
   source  = "terraform-aws-modules/rds/aws"
-  version = "6.3.1"
+  version = "6.4.0"
 
   identifier          = local.rds_identifier
   engine              = var.rds_engine