zvariant-2.6.0

• Disallow strings with interior null bytes. This will probably negatively effect performance but it's required to follow the spec.
• Implement a friendly Debug for ObjectPath.
• Allow efficient serialization and deserialization of byte arrays through serde_bytes crate. This has to be explicitly enabled through the serde_bytes feature and used via an explicit API.
• Provide more conversions:
  • From Owned/Value to Bitflags.
  • std::convert::Infallible to Error. Strictly speaking, this is an API break since error type inference in certain cases won't work and user will have to explicitly specify error types.
  • From <&*ObjectPath> to ObjectPath.
• Update repository links.