add change-tracker for new download-ci-llvm default

Signed-off-by: onur-ozkan <work@onurozkan.dev>

src/bootstrap/src/utils/change_tracker.rs

@@ -265,4 +265,9 @@ pub fn human_readable_changes(changes: &[ChangeInfo]) -> String {
         severity: ChangeSeverity::Info,
         summary: "New option `dist.vendor` added to control whether bootstrap should vendor dependencies for dist tarball.",
     },
+    ChangeInfo {
+        change_id: 130529,
+        severity: ChangeSeverity::Info,
+        summary: "If `llvm.download-ci-llvm` is not defined, it defaults to `true`.",
+    },
 ];