🔖 zbus 5.6.0

• 🚑️ Fix fdo::StatsProxy method return values. The return value of the methods were wrong so we fix it now. #1341
• 🚸 fdo::StatsProxy methods now return structs. Now that we can use serde derives directly, we can make use of the flatten attribute and have a very strongly-typed API for the statistics standardized by the D-Bus specification while still parsing and returning any bus broker specific statistics returned by these calls.
• 📝 Document fdo::StatsProxy.
• ⬆️a Require zvariant 5.5 and make use of its new API.
• ✨ Make OwnerChangedStream ordered. NameOwnerChangedStream is already ordered, so switching out the .map implementation and implementing OrderedStream is all that's needed.
• ✨ Expose low-level serial fields in builder.
• 🛂 Add support for ProcessFD/pid_fd credentials.
• ⚡️ Don't clone signature when creating body.
• ✅ Add body & signature getter to msg de benchmarks. This temporarily takes the benchmark go slower by 50%. This will be fixed in the next commit.
• ➖ Drop uneeded deps xdg-home & async-fs.
• ➖ Drop static_assertions dep.
• ✏️ Fix a typo in README.