### Description

Currently some code in RDS Operators use boto waiters and some uses a custom `_await_status`, the former is preferred over the later (waiters are vetted code provided by the boto sdk, they have features like exponential backoff, etc). See [this discussion thread](https://github.com/apache/airflow/pull/27076#discussion_r997325535) for more details/context.

### Use case/motivation

_No response_

### Related issues

_No response_

### Are you willing to submit a PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

self.log.info(
            "Starting to copy snapshot '%s' as '%s'",
            self.source_db_snapshot_identifier,
            self.target_db_snapshot_identifier,
        )
        if self.db_type.value == "instance":
            copy_instance_snap = self.hook.conn.copy_db_snapshot(
                SourceDBSnapshotIdentifier=self.source_db_snapshot_identifier,
                TargetDBSnapshotIdentifier=self.target_db_snapshot_identifier,
                KmsKeyId=self.kms_key_id,
                Tags=self.tags,
                CopyTags=self.copy_tags,
                PreSignedUrl=self.pre_signed_url,
                OptionGroupName=self.option_group_name,
                TargetCustomAvailabilityZone=self.target_custom_availability_zone,
                SourceRegion=self.source_region,
            )
            copy_response = json.dumps(copy_instance_snap, default=str)
            item_type = "instance_snapshot"
        else: