Update CHANGELOG for #6737

CHANGELOG.md

@@ -12,6 +12,7 @@ ENHANCEMENTS
 * data-source/aws_instance: Add `host_id` attribute [GH-6767]
 * data-source/aws_ip_ranges: Add `url` argument [GH-6756]
 * resource/aws_db_instance: Allow `postgresql` and `upgrade` values for `enabled_cloudwatch_logs_exports` (e.g. Postgres specific log exports) [GH-6829]
+* resource/aws_dynamodb_table: Allow `global_secondary_index` configuration block `read_capacity` and `write_capacity` to be omitted with `billing_mode` set to `PAY_PER_REQUEST` (support on-demand billing with GSIs) [GH-6737]
 * resource/aws_eks_cluster: Support `version` update [GH-6843]
 * resource/aws_glue_crawler: Add `security_configuration` argument [GH-6797]
 * resource/aws_iam_user_ssh_key: Support resource import [GH-6727]