Ensure copy tags to snapshots feature is enabled for Amazon Relational Database Service (Amazon RDS) clusters

AWS RDS instances have copy tags to snapshots feature disabled which may not allow you to add metadata and apply access policies to your AWS RDS resources.

In AWS Console -

1. Sign in to the AWS Console and open the RDS Console.
2. Under Databases, choose the cluster you wish to edit.
3. Select Modify.
4. Under Additional Configuration, in the Backup section, check the box for Copy tags to snapshots.

In Terraform -

1. In the aws_rds_cluster resource, set 'copy_tags_to_snapshot' to 'true'.

References:
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_CommonTasks.BackupRestore.html
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/rds_cluster#copy_tags_to_snapshot