Remove references to removed tools/gardening

Follow-up to 84ca34b

Change-Id: I87d2bf0a77dc70f15a378a149dc95be6f33ee3c9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/147803
Commit-Queue: Kevin Moore <kevmoo@google.com>
Commit-Queue: Karl Klose <karlklose@google.com>
Reviewed-by: Karl Klose <karlklose@google.com>

Author: kevmoo

.dart_tool/package_config.json

@@ -270,12 +270,6 @@
       "packageUri": "lib/",
       "languageVersion": "2.7"
     },
-    {
-      "name": "gardening",
-      "rootUri": "../tools/gardening",
-      "packageUri": "lib/",
-      "languageVersion": "2.7"
-    },
     {
       "name": "glob",
       "rootUri": "../third_party/pkg/glob",

.packages

@@ -44,7 +44,6 @@ ffi:third_party/pkg/ffi/lib
 fixnum:third_party/pkg/fixnum/lib
 frontend_server:pkg/frontend_server/lib
 front_end:pkg/front_end/lib
-gardening:tools/gardening/lib
 glob:third_party/pkg/glob/lib
 html:third_party/pkg/html/lib
 http:third_party/pkg/http/lib

tools/generate_package_config.dart

@@ -23,7 +23,6 @@ void main(List<String> args) {
     packageDirectory('sdk/lib/_internal/sdk_library_metadata'),
     packageDirectory('sdk/lib/_internal/js_runtime'),
     packageDirectory('third_party/pkg/protobuf/protobuf'),
-    packageDirectory('tools/gardening'),
   ];
 
   var cfePackageDirs = [