make nil version == unversioned in DeploymentVersionTransition

Author: carlydf

openapi/openapiv2.json

@@ -9818,10 +9818,8 @@
           "description": "Deprecated. Use `target`."
         },
         "deploymentVersion": {
-          "$ref": "#/definitions/v1WorkerDeploymentVersion"
-        },
-        "unversioned": {
-          "type": "boolean"
+          "$ref": "#/definitions/v1WorkerDeploymentVersion",
+          "description": "The target Version of the transition.\nIf nil, a so-far-versioned workflow is transitioning to unversioned workers."
         }
       },
       "description": "Holds information about ongoing transition of a workflow execution from one worker\ndeployment version to another.\nExperimental. Might change in the future."

openapi/openapiv3.yaml

@@ -7152,9 +7152,11 @@ components:
           type: string
           description: Deprecated. Use `target`.
         deploymentVersion:
-          $ref: '#/components/schemas/WorkerDeploymentVersion'
-        unversioned:
-          type: boolean
+          allOf:
+            - $ref: '#/components/schemas/WorkerDeploymentVersion'
+          description: |-
+            The target Version of the transition.
+             If nil, a so-far-versioned workflow is transitioning to unversioned workers.
       description: |-
         Holds information about ongoing transition of a workflow execution from one worker
          deployment version to another.

temporal/api/workflow/v1/message.proto

@@ -244,12 +244,9 @@ message DeploymentVersionTransition {
     // Deprecated. Use `target`.
     string version = 1 [deprecated = true];
 
-    // Required. The target Version of the transition. If `unversioned`, a
-    // so-far-versioned workflow is transitioning to unversioned workers.
-    oneof target {
-        temporal.api.deployment.v1.WorkerDeploymentVersion deployment_version = 2;
-        bool unversioned = 3;
-    }
+    // The target Version of the transition.
+    // If nil, a so-far-versioned workflow is transitioning to unversioned workers.
+    temporal.api.deployment.v1.WorkerDeploymentVersion deployment_version = 2;
 
     // Later: safe transition info
 }