Remove dead _resolvePackageUri implementation
Remove dead _resolvePackageUri implementation

The implementation for `Isolate.resolvePackageUri` is entirely within
`isolate_patch.dart`.

https://github.com/dart-lang/sdk/blob/b080e7c97a879eb803c725621b3993cbe994d19d/sdk/lib/_internal/js_runtime/lib/isolate_patch.dart#L33-L40

Change-Id: Ic2872369154f85814815d56b89ccc227af5434ad
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/104602
Reviewed-by: Sigmund Cherem <beaea8fd7d2a56555046ba4f362c8a93e3938576@google.com>
Commit-Queue: Nate Bosch <dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com>

dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk