BlendFileBlock attributes: Explicit annotation on BlendFileBlock are needed because otherwise e.g. `block.add_old` type was imprecisely inferred from the assignments as `int | Any`, where `Any` comes from `.unpack` returning `tuple[Any, ...]`. Ideally unpack should be somehow connected to the returned types, but this solution should work for now just to avoid typing errors. dna_io - add some missing annotations: Some annotations were needed to ensure `block.code` will be inferred as `bytes` and not `bytes | Unknown`. Reviewed-on: https://projects.blender.org/blender/blender-asset-tracer/pulls/92897 Reviewed-by: Sybren A. Stüvel <sybren@blender.org>