Remove unused dependency on package:meta (dart-archive/test_descriptor#31)

Author: natebosch

pkgs/test_descriptor/CHANGELOG.md

@@ -1,3 +1,5 @@
+## 2.0.0-nullsafety.1-dev
+
 ## 2.0.0-nullsafety
 
 * Migrate to null safety.

pkgs/test_descriptor/pubspec.yaml

@@ -1,5 +1,5 @@
 name: test_descriptor
-version: 2.0.0-nullsafety
+version: 2.0.0-nullsafety.1-dev
 description: An API for defining and verifying directory structures.
 homepage: https://github.com/dart-lang/test_descriptor
 
@@ -10,7 +10,6 @@ dependencies:
   async: ^2.5.0-nullsafety
   collection: ^1.15.0-nullsafety
   matcher: ^0.12.10-nullsafety
-  meta: ^1.3.0-nullsafety
   path: ^1.8.0-nullsafety
   term_glyph: ^ 1.2.0-nullsafety
   test: ^1.16.0-nullsafety