feat: add OrderStatusCode values to reflect failure modes for orders (#56)

## What I'm changing

- Adding FAILED and EXPIRED OrderStatusCodes
We may get away with grouping those two failure modes into a single
code, but I think we should have one.


## Checklist

- [X ] Tests pass: `uv run pytest`
- [ ] Checks pass: `uv run pre-commit --all-files` 
FYI: `pre-commit: error: unrecognized arguments: --all-files`

- [ ] CHANGELOG is updated (if necessary)

---------

Co-authored-by: Pete Gadomski <[email protected]>

Author: nic-planet

stapi-pydantic/src/stapi_pydantic/order.py

@@ -43,6 +43,8 @@ class OrderStatusCode(StrEnum):
     reserved = "reserved"
     tasked = "tasked"
     user_cancelled = "user_cancelled"
+    expired = "expired"
+    failed = "failed"
 
 
 class OrderStatus(BaseModel):