[build_test] update dependencies, prepare v2.2.2 release (#3626)

Also bumped deps in example

Author: kevmoo

build_test/CHANGELOG.md

@@ -1,6 +1,7 @@
-## 2.2.2-wip
+## 2.2.2
 
 - Bump the min sdk to 3.0.0.
+- Support the latest version of `package:test_core`.
 
 ## 2.2.1
 

build_test/pubspec.yaml

@@ -1,6 +1,6 @@
 name: build_test
 description: Utilities for writing unit tests of Builders.
-version: 2.2.2-wip
+version: 2.2.2
 repository: https://github.com/dart-lang/build/tree/master/build_test
 
 environment:
@@ -20,7 +20,7 @@ dependencies:
   path: ^1.8.0
   stream_transform: ^2.0.0
   test: ^1.16.0
-  test_core: '>=0.3.19 <0.6.0'
+  test_core: '>=0.3.19 <0.7.0'
   watcher: ^1.0.0
 
 dev_dependencies:

example/pubspec.yaml

@@ -11,5 +11,5 @@ dependencies:
 
 dev_dependencies:
   build_runner: ^2.0.0
-  build_web_compilers: ^3.0.0
+  build_web_compilers: ^4.0.0
   dart_flutter_team_lints: ^2.0.0