fix: fix jobs api literal return type (#1757)

# What does this PR do?

- We cannot directly return a literal type

> Note: this is not final jobs API change

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])

## Test Plan
<img width="837" alt="image"
src="https://github.com/user-attachments/assets/18a17561-35f9-443d-987d-54afdd6ff40c"
/>


[//]: # (## Documentation)

llama_stack/apis/common/job_types.py

@@ -10,14 +10,14 @@ from pydantic import BaseModel
 from llama_stack.schema_utils import json_schema_type
 
 
-@json_schema_type
-class Job(BaseModel):
-    job_id: str
-
-
-@json_schema_type
 class JobStatus(Enum):
     completed = "completed"
     in_progress = "in_progress"
     failed = "failed"
     scheduled = "scheduled"
+
+
+@json_schema_type
+class Job(BaseModel):
+    job_id: str
+    status: JobStatus