the trait bound Task is not satisfied

[Mossaka]

When compiling containerd-shim v0.7.1 crate, I got the following error:

error[E0277]: the trait bound `std::boxed::Box<<T as synchronous::Shim>::T>: Task` is not satisfied
   --> /home/mossaka/.cargo/registry/src/index.crates.io-6f17d22bba15001f/containerd-shim-0.7.1/src/synchronous/mod.rs:267:44
    |
267 |             let task_service = create_task(Arc::new(Box::new(task)));
    |                                            ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Task` is not implemented for `std::boxed::Box<<T as synchronous::Shim>::T>`
    |
    = note: required for the cast from `Arc<std::boxed::Box<<T as synchronous::Shim>::T>>` to `Arc<(dyn Task + Send + Sync + 'static)>`

For more information about this error, try `rustc --explain E0277`.
error: could not compile `containerd-shim` (lib) due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: failed to verify package tarball

This is blocking the runwasi release pipeline to publish a new crate version.

[Mossaka]

Fixed by #321