Handle `RegistryAuth::Bearer` for `wkg oci` subcommands

[mkatychev]

Current implementation does not allow for passing in a bearer token

wasm-pkg-tools/crates/wkg/src/oci.rs

Lines 35 to 67 in dfa2e17

	impl Auth {
	fn into_auth(self, reference: &Reference) -> anyhow::Result<RegistryAuth> {
	match (self.username, self.password) {
	(Some(username), Some(password)) => Ok(RegistryAuth::Basic(username, password)),
	(None, None) => {
	let server_url = Self::get_docker_config_auth_key(reference);
	match docker_credential::get_credential(server_url) {
	Ok(DockerCredential::UsernamePassword(username, password)) => {
	return Ok(RegistryAuth::Basic(username, password));
	}
	Ok(DockerCredential::IdentityToken(_)) => {
	return Err(anyhow::anyhow!("identity tokens not supported"));
	}
	Err(err) => {
	tracing::debug!(
	"Failed to look up OCI credentials with key `{server_url}`: {err}"
	);
	}
	}
	Ok(RegistryAuth::Anonymous)
	}
	_ => Err(anyhow::anyhow!("Must provide both a username and password")),
	}
	}
	/// Translate the registry into a key for the auth lookup.
	fn get_docker_config_auth_key(reference: &Reference) -> &str {
	match reference.resolve_registry() {
	"index.docker.io" => "https://index.docker.io/v1/", // Default registry uses this key.
	other => other, // All other registries are keyed by their domain name without the `https://` prefix or any path suffix.
	}
	}
	}

And oras config files are not checked:

wasm-pkg-tools/crates/wkg/src/oci.rs

Line 41 in dfa2e17

match docker_credential::get_credential(server_url) {