oci-distribution v0.8.1

This is a patch release that contains the following fixes:

• ClientConfig: define accept_invalid_hostnames attribute only when native-tls is being used
• Improve parsing of container image names: this ensure Reference behaves in the same way as native Go libraries do when parsing oci names
• Fix interactions with GitHub Container Registry: ensure anonymous operations (like pull) can be performed

The following cleanups have been done:

• Remove Cargo.lock file from repository
• Remove the in-tree version of the www-authenticate crate: use the latest official release of it, which contains all the changes and fixes oci-distribution did.
• Fix all clippy warnings
• Fix cargo deny execution