[ffigen] Prepare to publish ffigen 16.1.0

[liamappelbe]

Prepare to publish package:ffigen 16.1.0 and package:objective_c 4.1.0

[github-actions]

PR Health

Changelog Entry ✔️

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

API leaks ⚠️

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbols
objective_c	ObjCBlockBase c._ObjCBlockImpl _ObjCBlockDesc _ObjCBlockRef _ObjCObject _Dart_FinalizableHandle _ObjCProtocol _ObjCSelector _ObjCMethodDesc _ObjCObjectRef _NSZone

This check can be disabled by tagging the PR with skip-leaking-check.

License Headers ✔️

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
no missing headers

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/jni/lib/src/third_party/generated_bindings.dart
pkgs/objective_c/lib/src/ns_input_stream.dart

[coveralls]

coverage: 87.434%. remained the same
when pulling c632cf9 on ffigen_16_1
into 7c7cced on main.