Resynchronize from #2509 (#2510)

Author: nex3

lib/src/environment.dart

@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_environment.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: e1beeae58a4d5b97cd7d4f01c7d46b0586b508b9
+// Checksum: 3698889f94437e131e4d581757d1538fd46be497
 //
 // ignore_for_file: unused_import