Add bootstrap changelog entry

Author: bjorn3

src/bootstrap/src/utils/change_tracker.rs

@@ -111,4 +111,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Warning,
         summary: "A new `optimized-compiler-builtins` option has been introduced. Whether to build llvm's `compiler-rt` from source is no longer implicitly controlled by git state. See the PR for more details.",
     },
+    ChangeInfo {
+        change_id: 120348,
+        severity: ChangeSeverity::Info,
+        summary: "New option `target.<triple>.codegen-backends` added to config.toml.",
+    },
 ];