fix: don't mask backend errors

The backend should always write compliant response codes.
This change removes a work around for the case where it failed to
correctly set 202

datatrails_scitt_samples/statement_registration.py

@@ -78,9 +78,6 @@ def get_operation_status(ctx: ServiceContext, operation_id: str) -> dict:
     response.raise_for_status()
     if response.status_code == 202:
         return {"Status": "running"}
-    if not response.content:
-        ctx.info(f"no content and status code {response.status_code} != 202, assuming running")
-        return {"Status": "running"}
     return decode_cbor_data(response.content)