Upgrade to package:objective_c` 4.0

[brianquinlan]

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

Contribution guidelines:

• See our contributor guide for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Contributions to our repos should follow the Dart style guide and use dart format.
• Most changes should add an entry to the changelog and may need to rev the pubspec package version.
• Changes to packages require corresponding tests.

Note that many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

[github-actions]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:http2	2.3.1	ready to publish	http2-v2.3.1
package:cronet_http	1.3.3-wip	WIP (no publish necessary)
package:cupertino_http	2.0.2-wip	WIP (no publish necessary)
package:http	1.3.0-wip	WIP (no publish necessary)
package:http_parser	4.1.1	already published at pub.dev
package:http_profile	0.1.1-wip	WIP (no publish necessary)
package:ok_http	0.1.1-wip	WIP (no publish necessary)
package:web_socket	0.1.6	already published at pub.dev

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[github-actions]

PR Health

Changelog Entry ✔️

Package	Changed Files

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

Coverage ⚠️

File	Coverage
pkgs/cupertino_http/example/integration_test/utils_test.dart	💔 Not covered
pkgs/cupertino_http/lib/src/cupertino_api.dart	💔 Not covered
pkgs/cupertino_http/lib/src/native_cupertino_bindings.dart	💔 Not covered

This check for test coverage is informational (issues shown here will not fail the PR).

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

License Headers ⚠️

// Copyright (c) 2024, 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
pkgs/cupertino_http/lib/src/native_cupertino_bindings.dart

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/cronet_http/lib/src/jni/jni_bindings.dart
pkgs/http/example/main.dart
pkgs/http2/test/src/flowcontrol/mocks.mocks.dart
pkgs/http_client_conformance_tests/example/client_test.dart
pkgs/http_client_conformance_tests/lib/src/compressed_response_body_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/compressed_response_body_server_web.dart
pkgs/http_client_conformance_tests/lib/src/dummy_isolate.dart
pkgs/http_client_conformance_tests/lib/src/multipart_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/multipart_server_web.dart
pkgs/http_client_conformance_tests/lib/src/multiple_clients_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/multiple_clients_server_web.dart
pkgs/http_client_conformance_tests/lib/src/redirect_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/redirect_server_web.dart
pkgs/http_client_conformance_tests/lib/src/request_body_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/request_body_server_web.dart
pkgs/http_client_conformance_tests/lib/src/request_body_streamed_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/request_body_streamed_server_web.dart
pkgs/http_client_conformance_tests/lib/src/request_cookies_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/request_cookies_server_web.dart
pkgs/http_client_conformance_tests/lib/src/request_headers_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/request_headers_server_web.dart
pkgs/http_client_conformance_tests/lib/src/request_methods_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/request_methods_server_web.dart
pkgs/http_client_conformance_tests/lib/src/response_body_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/response_body_server_web.dart
pkgs/http_client_conformance_tests/lib/src/response_body_streamed_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/response_body_streamed_server_web.dart
pkgs/http_client_conformance_tests/lib/src/response_cookies_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/response_cookies_server_web.dart
pkgs/http_client_conformance_tests/lib/src/response_headers_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/response_headers_server_web.dart
pkgs/http_client_conformance_tests/lib/src/response_status_line_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/response_status_line_server_web.dart
pkgs/http_client_conformance_tests/lib/src/server_errors_server_vm.dart
pkgs/http_client_conformance_tests/lib/src/server_errors_server_web.dart
pkgs/http_parser/test/example_test.dart
pkgs/http_profile/lib/http_profile.dart
pkgs/ok_http/lib/src/jni/bindings.dart
pkgs/web_socket/example/web_socket_example.dart
pkgs/web_socket/lib/testing.dart
pkgs/web_socket_conformance_tests/example/client_test.dart
pkgs/web_socket_conformance_tests/lib/src/close_local_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/close_local_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/close_remote_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/close_remote_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/continuously_writing_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/continuously_writing_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/disconnect_after_upgrade_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/disconnect_after_upgrade_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/echo_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/echo_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/no_upgrade_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/no_upgrade_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/peer_protocol_errors_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/peer_protocol_errors_server_web.dart
pkgs/web_socket_conformance_tests/lib/src/protocol_server_vm.dart
pkgs/web_socket_conformance_tests/lib/src/protocol_server_web.dart

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