Update links to repos that moved to dart-lang/native (#5651)

Fixes #5625

Author: parlough

src/content/interop/java-interop.md

@@ -149,7 +149,7 @@ The following are some more comprehensive examples of using `package:jnigen`:
 {:.table}
 
 [dev dependency]: /tools/pub/dependencies#dev-dependencies
-[in_app_java]: https://github.com/dart-lang/jnigen/tree/main/jnigen/example/in_app_java
-[notification_plugin]: https://github.com/dart-lang/jnigen/tree/main/jnigen/example/notification_plugin
-[pdfbox_plugin]: https://github.com/dart-lang/jnigen/tree/main/jnigen/example/pdfbox_plugin
+[in_app_java]: https://github.com/dart-lang/native/tree/main/pkgs/jnigen/example/in_app_java
+[notification_plugin]: https://github.com/dart-lang/native/tree/main/pkgs/jnigen/example/notification_plugin
+[pdfbox_plugin]: https://github.com/dart-lang/native/tree/main/pkgs/jnigen/example/pdfbox_plugin
 [Apache PDFBox]: https://pdfbox.apache.org/

src/content/interop/objective-c-interop.md

@@ -2,7 +2,7 @@
 title: "Objective-C and Swift interop using package:ffigen"
 description: "To use Objective-C and Swift code in your Dart program, use package:ffigen."
 ffigen: "https://pub.dev/packages/ffigen"
-example: "https://github.com/dart-lang/ffigen/tree/master/example/objective_c"
+example: "https://github.com/dart-lang/native/tree/main/pkgs/ffigen/example/objective_c"
 appledoc: "https://developer.apple.com/documentation"
 ---
 
@@ -545,4 +545,4 @@ $ dart run example.dart
 [`package:cupertino_http`]: https://github.com/dart-lang/http/blob/master/pkgs/cupertino_http/src/CUPHTTPClientDelegate.m
 [not thread safe]: https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Multithreading/ThreadSafetySummary/ThreadSafetySummary.html
 [Objective-C dispatch documentation]: {{appledoc}}/dispatch?language=objc
-[swift_example]: https://github.com/dart-lang/ffigen/tree/main/example/swift
+[swift_example]: https://github.com/dart-lang/native/tree/main/pkgs/ffigen/example/swift