fix: adds dynamodb:ConditionCheckItem permission to dynamodb construct

Without this IAM permission, transacted writes in dynamodb using the `ConditionCheck` feature are disallowed.

See:

https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_ConditionCheck.html

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/transaction-apis-iam.html

src/constructs/aws/DatabaseDynamoDBSingleTable.ts

@@ -86,6 +86,7 @@ export class DatabaseDynamoDBSingleTable extends AwsConstruct {
                     "dynamodb:DeleteItem",
                     "dynamodb:BatchWriteItem",
                     "dynamodb:UpdateItem",
+                    "dynamodb:ConditionCheckItem",
                 ],
                 [this.table.tableArn, Stack.of(this).resolve(Fn.join("/", [this.table.tableArn, "index", "*"]))]
             ),