update changelog

Author: rcoh

CHANGELOG.next.toml

@@ -15,3 +15,9 @@ message = "Upgrade to Gradle 7. This change is not a breaking change, however, u
 references = ["smithy-rs#1411", "smithy-rs#1167"]
 meta = { "breaking" = false, "tada" = true, "bug" = false }
 author = "rcoh"
+
+[[aws-sdk-rust]]
+message = "Add a trailing slash to the URI `/latest/meta-data/iam/security-credentials/ when loading credentials from IMDS"
+references = ["aws-sdk-rust#560", "smithy-rs#1487"]
+meta = { "breaking" = false, "tada" = false, "bug" = true }
+author = "rcoh"