Update native-image/preserve-package/README.md

Author: ban-mi

native-image/preserve-package/README.md

@@ -222,3 +222,4 @@ As shown:
   https://www.graalvm.org/latest/reference-manual/native-image/metadata/AutomaticMetadataCollection/#tracing-agent
 - Java Reflection API (JDK 25):
   https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/reflect/package-summary.html
+  - Native Image Build Report: https://www.graalvm.org/latest/reference-manual/native-image/overview/build-report/