Add dependency to yaml_edit and bump pub revision

Change-Id: Iaec41d7308c7ebe2a78a3c578b91c56cdad97e12
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/214280
Commit-Queue: Sarah Zakarias <zarah@google.com>
Reviewed-by: Jonas Jensen <jonasfj@google.com>

.dart_tool/package_config.json

@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2021-09-21T21:00:34.058842",
+  "generated": "2021-09-23T11:31:05.389095",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -810,6 +810,12 @@
       "rootUri": "../third_party/pkg/yaml",
       "packageUri": "lib/",
       "languageVersion": "2.12"
+    },
+    {
+      "name": "yaml_edit",
+      "rootUri": "../third_party/pkg/yaml_edit",
+      "packageUri": "lib/",
+      "languageVersion": "2.12"
     }
   ]
 }