Update CHANGELOG.md for hashicorp#40278

CHANGELOG.md

@@ -9,6 +9,8 @@ BUG FIXES:
 * provider: Suppress `Warning: AWS account ID not found for provider` when `skip_requesting_account_id` is `true` ([#40264](https://github.com/hashicorp/terraform-provider-aws/issues/40264))
 * resource/aws_batch_job_definition: Fix crash when specifying `eksProperties` or `ecsProperties` block ([#40172](https://github.com/hashicorp/terraform-provider-aws/issues/40172))
 * resource/aws_chatbot_slack_channel_configuration: Fix inconsistent provider result when order of `sns_topic_arns`changes ([#40253](https://github.com/hashicorp/terraform-provider-aws/issues/40253))
+* resource/aws_db_instance: When changing `storage_type` from `io1` or `io2` to `gp3`, fix bug causing error `InvalidParameterCombination: You must specify both the storage size and iops when modifying the storage size or iops on a DB instance that has iops` ([#37257](https://github.com/hashicorp/terraform-provider-aws/issues/37257))
+* resource/aws_db_instance: When changing a `gp3` volume's `allocated_storage` to a value larger than the [threshold value for `engine`](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_Storage.html#gp3-storage), fix bug causing error `InvalidParameterCombination: You must specify both the storage size and iops when modifying the storage size or iops on a DB instance that has iops` ([#28847](https://github.com/hashicorp/terraform-provider-aws/issues/28847))
 
 ## 5.77.0 (November 21, 2024)