[dart2js] Fix sdk yaml files.

Fixes unittest-weak-asserts-no-sdk-linux pkg/compiler/test/end_to_end/no_platform_test

It is a total mystery though why this was passing before migrating sdk_nnbd to sdk.

Change-Id: Id71efb2c1b399ca64233b3544d2f274d63690aa6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/151468
Commit-Queue: Joshua Litt <joshualitt@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>

.dart_tool/package_config.json

@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2020-06-16T15:18:03.429449",
+  "generated": "2020-06-17T09:39:51.245406",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -339,7 +339,7 @@
       "name": "js_runtime",
       "rootUri": "../sdk/lib/_internal/js_runtime",
       "packageUri": "lib/",
-      "languageVersion": "2.0"
+      "languageVersion": "2.9"
     },
     {
       "name": "json_rpc_2",
@@ -410,7 +410,7 @@
       "name": "native_stack_traces",
       "rootUri": "../pkg/native_stack_traces",
       "packageUri": "lib/",
-      "languageVersion": "2.7"
+      "languageVersion": "2.8"
     },
     {
       "name": "nnbd_migration",
@@ -493,7 +493,7 @@
       "name": "sdk_library_metadata",
       "rootUri": "../sdk/lib/_internal/sdk_library_metadata",
       "packageUri": "lib/",
-      "languageVersion": "2.0"
+      "languageVersion": "2.9"
     },
     {
       "name": "shelf",

sdk/lib/_internal/js_runtime/pubspec.yaml

@@ -3,4 +3,4 @@
 name: js_runtime
 publish_to: none
 environment:
-  sdk: '>=2.0.0 <3.0.0'
+  sdk: '>=2.9.0-1 <3.0.0'

sdk/lib/_internal/sdk_library_metadata/pubspec.yaml

@@ -3,4 +3,4 @@
 name: sdk_library_metadata
 publish_to: none
 environment:
-  sdk: '>=2.0.0 <3.0.0'
+  sdk: '>=2.9.0-1 <3.0.0'