Version 0.5.0

• Support tagged unions for encoding/decoding a Union of msgspec.Struct types.
• Further improve encoding performance of enum.Enum by 20-30%
• Reduce overhead of calling msgspec.json.decode/msgspec.msgpack.decode with type=SomeStructType. It's still faster to create a Decoder once and call decoder.decode multiple times, but for struct types the overhead of calling the top-level function is decreased significantly.
• Rename the Struct option asarray to array_like (a breaking change)