std-embedded-nal-async 0.4.0

Implementation of the `embedded-nal-async` traits for large devices that support the standard library
Documentation
# Changes in 0.4.0

* embedded-nal-async dependency changed from 0.8 to 0.9.
* Replaced async-std with async-net and other smol components.
* Limited construction of Stack through explicit `.default()` construction.
* Added examples.
* Bump MSRV to 1.81.

# Changes in 0.3.0

* embedded-nal dependency changed from 0.7 to 0.8.
* Bump MSRV to 1.77.
* Removed explicit lifetime annotation from TcpConnect::connect.
* README and metadata fixes.

# Changes in 0.2.0

* embedded-nal-async dependency changed from 0.6 to 0.7.

  The one user visible change is the update of the `Dns::get_host_by_address` signature,