Update

Author: mosuem

.github/CODEOWNERS

@@ -1,13 +1,13 @@
 pkgs/args           @munificent
 pkgs/async          @dart-ecosystem-admins
-pkgs/characters     @dart-ecosystem-admins
+pkgs/characters     @lrhn
 pkgs/collection     @dart-ecosystem-admins
 pkgs/convert        @dart-ecosystem-admins
 pkgs/crypto         @dart-ecosystem-admins
-pkgs/fixnum         @lrhn
+pkgs/fixnum         @dart-ecosystem-admins #?
 pkgs/lints          @dart-ecosystem-admins
 pkgs/logging        @dart-ecosystem-admins
-pkgs/os_detect      @dart-ecosystem-admins
+pkgs/os_detect      @lrhn
 pkgs/path           @munificent
 pkgs/platform       @lrhn
 pkgs/typed_data     @dart-ecosystem-admins