Update CHANGELOG.md for #31396

Author: changelogbot

CHANGELOG.md

@@ -34,6 +34,7 @@ BREAKING CHANGES:
 * resource/aws_dms_endpoint: `s3_settings.ignore_headers_row` has been removed ([#30452](https://github.com/hashicorp/terraform-provider-aws/issues/30452))
 * resource/aws_docdb_cluster: `snapshot_identifier` change now properly forces replacement ([#29409](https://github.com/hashicorp/terraform-provider-aws/issues/29409))
 * resource/aws_ec2_client_vpn_endpoint: The `status` attribute has been removed ([#31223](https://github.com/hashicorp/terraform-provider-aws/issues/31223))
+* resource/aws_ec2_client_vpn_network_association: The `security_groups` attribute has been removed ([#31396](https://github.com/hashicorp/terraform-provider-aws/issues/31396))
 * resource/aws_ec2_client_vpn_network_association: The `status` attribute has been removed ([#31223](https://github.com/hashicorp/terraform-provider-aws/issues/31223))
 * resource/aws_ecs_cluster: The `capacity_providers` and `default_capacity_provider_strategy` attributes have been removed ([#31346](https://github.com/hashicorp/terraform-provider-aws/issues/31346))
 * resource/aws_eip: With the retirement of EC2-Classic the `standard` domain is no longer supported ([#30966](https://github.com/hashicorp/terraform-provider-aws/issues/30966))