make version optional for versioning override of already-pinned workflows

Author: carlydf

openapi/openapiv2.json

@@ -7888,7 +7888,7 @@
         },
         "version": {
           "$ref": "#/definitions/v1WorkerDeploymentVersion",
-          "description": "Required."
+          "description": "Specifies the Worker Deployment Version to pin this workflow to.\nRequired if the target workflow is not already pinned to a version.\n\nIf omitted and the target workflow is already pinned, the effective\npinned version will be the existing pinned version.\n\nIf omitted and the target workflow is not pinned, the override request\nwill be rejected with a PreconditionFailed error."
         }
       }
     },

openapi/openapiv3.yaml

@@ -13495,7 +13495,15 @@ components:
         version:
           allOf:
             - $ref: '#/components/schemas/WorkerDeploymentVersion'
-          description: Required.
+          description: |-
+            Specifies the Worker Deployment Version to pin this workflow to.
+             Required if the target workflow is not already pinned to a version.
+
+             If omitted and the target workflow is already pinned, the effective
+             pinned version will be the existing pinned version.
+
+             If omitted and the target workflow is not pinned, the override request
+             will be rejected with a PreconditionFailed error.
     WaitPolicy:
       type: object
       properties:

temporal/api/workflow/v1/message.proto

@@ -587,7 +587,15 @@ message VersioningOverride {
         // Defaults to PINNED_OVERRIDE_BEHAVIOR_UNSPECIFIED.
         // See `PinnedOverrideBehavior` for details.
         PinnedOverrideBehavior behavior = 1;
-        // Required.
+
+        // Specifies the Worker Deployment Version to pin this workflow to.
+        // Required if the target workflow is not already pinned to a version.
+        //
+        // If omitted and the target workflow is already pinned, the effective
+        // pinned version will be the existing pinned version.
+        //
+        // If omitted and the target workflow is not pinned, the override request
+        // will be rejected with a PreconditionFailed error.
         temporal.api.deployment.v1.WorkerDeploymentVersion version = 2;
     }