add change tracking

Author: pietroalbini

src/bootstrap/src/utils/change_tracker.rs

@@ -355,4 +355,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Info,
         summary: "It is now possible to configure `jemalloc` for each target",
     },
+    ChangeInfo {
+        change_id: 137220,
+        severity: ChangeSeverity::Info,
+        summary: "rust.channel now supports \"ci\" to load the channel from `src/ci/channel`",
+    },
 ];