Remove the matcher export from test_api (#2004)

`package:test` exports directly from `package:matcher`. Resolves a
cyclic dependency between `matcher` and `test_api`.
diff --git a/pkgs/test/pubspec.yaml b/pkgs/test/pubspec.yaml
index 8667d36..00c153a 100644
--- a/pkgs/test/pubspec.yaml
+++ b/pkgs/test/pubspec.yaml
@@ -32,11 +32,11 @@
   webkit_inspection_protocol: ^1.0.0
   yaml: ^3.0.0
   # Use an exact version until the test_api and test_core package are stable.
-  test_api: 0.5.3
+  test_api: 0.6.0
   test_core: 0.5.3
   # Use a tight version constraint to ensure that a constraint on matcher
   # properly constrains all features it provides.
-  matcher: '>=0.12.15 <0.12.16'
+  matcher: '>=0.12.16 <0.12.17'
 
 dev_dependencies:
   fake_async: ^1.0.0
diff --git a/pkgs/test_api/CHANGELOG.md b/pkgs/test_api/CHANGELOG.md
index 4d79f0a..6606ee9 100644
--- a/pkgs/test_api/CHANGELOG.md
+++ b/pkgs/test_api/CHANGELOG.md
@@ -1,5 +1,7 @@
-## 0.5.3-wip
+## 0.6.0-wip
 
+* Remove the `package:test_api/expect.dart' library. `test` will export from
+  `package:matcher` directly.
 * Fix compatibility with wasm number semantics.
 
 ## 0.5.2
diff --git a/pkgs/test_api/lib/expect.dart b/pkgs/test_api/lib/expect.dart
deleted file mode 100644
index 5e62622..0000000
--- a/pkgs/test_api/lib/expect.dart
+++ /dev/null
@@ -1,5 +0,0 @@
-// Copyright (c) 2021, 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.
-
-export 'package:matcher/expect.dart';
diff --git a/pkgs/test_api/lib/src/expect/async_matcher.dart b/pkgs/test_api/lib/src/expect/async_matcher.dart
deleted file mode 100644
index 044c192..0000000
--- a/pkgs/test_api/lib/src/expect/async_matcher.dart
+++ /dev/null
@@ -1,5 +0,0 @@
-// Copyright (c) 2017, 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.
-
-export 'package:matcher/src/expect/async_matcher.dart';
diff --git a/pkgs/test_api/lib/test_api.dart b/pkgs/test_api/lib/test_api.dart
index 17a1ef4..7804cda 100644
--- a/pkgs/test_api/lib/test_api.dart
+++ b/pkgs/test_api/lib/test_api.dart
@@ -6,7 +6,5 @@
     'Please use package:test.')
 library test_api;
 
-export 'package:matcher/expect.dart';
-
 export 'hooks.dart' show TestFailure;
 export 'scaffolding.dart';
diff --git a/pkgs/test_api/pubspec.yaml b/pkgs/test_api/pubspec.yaml
index 651b4b9..84142f9 100644
--- a/pkgs/test_api/pubspec.yaml
+++ b/pkgs/test_api/pubspec.yaml
@@ -1,5 +1,5 @@
 name: test_api
-version: 0.5.3-wip
+version: 0.6.0-wip
 description: >-
   The user facing API for structuring Dart tests and checking expectations.
 repository: https://github.com/dart-lang/test/tree/master/pkgs/test_api
@@ -18,10 +18,6 @@
   string_scanner: ^1.1.0
   term_glyph: ^1.2.0
 
-  # Use a tight version constraint to ensure that a constraint on matcher
-  # properly constrains all features it provides.
-  matcher: '>=0.12.15 <0.12.16'
-
 dev_dependencies:
   analyzer: '>=2.1.0 <6.0.0'
   fake_async: ^1.2.0
diff --git a/pkgs/test_core/lib/test_core.dart b/pkgs/test_core/lib/test_core.dart
index 55c7a50..01f4454 100644
--- a/pkgs/test_core/lib/test_core.dart
+++ b/pkgs/test_core/lib/test_core.dart
@@ -7,7 +7,5 @@
 library test_core;
 
 export 'package:test_api/hooks.dart' show TestFailure;
-// Not yet deprecated, but not exposed through focused libraries.
-export 'package:test_api/test_api.dart' show registerException;
 
 export 'scaffolding.dart';
diff --git a/pkgs/test_core/pubspec.yaml b/pkgs/test_core/pubspec.yaml
index a19ded3..2e5bb2a 100644
--- a/pkgs/test_core/pubspec.yaml
+++ b/pkgs/test_core/pubspec.yaml
@@ -27,10 +27,8 @@
   stream_channel: ^2.1.0
   vm_service: ">=6.0.0 <12.0.0"
   yaml: ^3.0.0
-  # matcher is tightly constrained by test_api
-  matcher: ^0.12.11
   # Use an exact version until the test_api package is stable.
-  test_api: 0.5.3
+  test_api: 0.6.0
 
 dev_dependencies:
   lints: '>=1.0.0 <3.0.0'