Attributes of ReactionRules are not inherited in `expand`

```python
from ecell4.prelude import *

with reaction_rules():
    A > B | 0.0 | {"name": "rr1"}
    
m = get_model(is_netfree=True)

for rr in m.reaction_rules():
    print(rr.as_string(), rr.list_attributes())
# A>B|0 [('name', 'rr1')]

for rr in m.expand([Species("A")]).reaction_rules():
    print(rr.as_string(), rr.list_attributes())
# A>B|0 []
```