feat: add run state PREEMPTED (#188)

* Add in PREEMPTED.

* Resolve reorganization of yaml's into 1 single yaml.

Author: vsmalladi

openapi/workflow_execution_service.openapi.yaml

@@ -506,6 +506,7 @@ components:
         - SYSTEM_ERROR
         - CANCELED
         - CANCELING
+        - PREEMPTED
       type: string
       description: >
         State can take any of the following values:
@@ -532,6 +533,10 @@ components:
           + CANCELED: The task was canceled by the user.
 
           + CANCELING: The task was canceled by the user, and is in the process of stopping.
+
+          + PREEMPTED: The task is stopped (preempted) by the system. The reasons for this would be tied to
+        the specific system running the job. Generally, this means that the system reclaimed the compute
+        capacity for reallocation.
     RunStatus:
       title: RunStatus
       required: