Update pubspecs to null-safe dependencies

lib/web_ui/analysis_options.yaml

@@ -3,6 +3,8 @@
 # uncommented, we'll delete this file and simply inherit the root options.
 
 analyzer:
+  exclude:
+    - build/**
   enable-experiment:
     - non-nullable
   strong-mode:

lib/web_ui/dev/test_runner.dart

@@ -236,7 +236,7 @@ class TestCommand extends Command<bool> with ArgUtils {
     }
 
     // Separate HTML targets from CanvasKit targets because the two use
-    // different dart2js options (and different build.*.yaml files).
+    // different dart2js options.
     final List<FilePath> htmlTargets = <FilePath>[];
     final List<FilePath> canvasKitTargets = <FilePath>[];
     final String canvasKitTestDirectory =

lib/web_ui/pubspec.yaml

@@ -5,22 +5,18 @@ environment:
   sdk: ">=2.10.0-0 <3.0.0"
 
 dependencies:
-  meta: 1.1.8
+  js: 0.6.3-nullsafety.3
+  meta: 1.3.0-nullsafety.6
 
 dev_dependencies:
   analyzer: 0.39.15
   archive: 2.0.13
   http: 0.12.1
   image: 2.1.13
-  js: 0.6.1+1
   mockito: 4.1.1
   path: 1.8.0-nullsafety.3
-  test: 1.14.3
-  quiver: 2.1.3
-  build_resolvers: 1.3.10
-  build_runner: 1.10.0
-  build_test: 1.0.0
-  build_web_compilers: 2.11.0
+  test: 1.16.0-nullsafety.9
+  quiver: 3.0.0-nullsafety.2
   yaml: 2.2.1
   watcher: 0.9.7+15
   web_test_utils:

web_sdk/web_engine_tester/pubspec.yaml

@@ -4,9 +4,9 @@ environment:
   sdk: ">=2.2.0 <3.0.0"
 
 dependencies:
-  js: 0.6.1+1
-  stream_channel: 2.0.0
-  test: 1.14.3
+  js: 0.6.3-nullsafety.3
+  stream_channel: 2.1.0-nullsafety.3
+  test: 1.16.0-nullsafety.9
   webkit_inspection_protocol: 0.5.0
   ui:
     path: ../../lib/web_ui

web_sdk/web_test_utils/pubspec.yaml

@@ -6,5 +6,5 @@ environment:
 dependencies:
   path: 1.8.0-nullsafety.3
   image: 2.1.13
-  js: 0.6.1+1
+  js: 0.6.3-nullsafety.3
   yaml: 2.2.1