[Inference API] Fix serialization for inference delete endpoint response (#110431)

Author: maxhniebergall

docs/changelog/110431.yaml

@@ -0,0 +1,5 @@
+pr: 110431
+summary: "[Inference API] Fix serialization for inference delete endpoint response"
+area: Machine Learning
+type: bug
+issues: []

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/inference/action/DeleteInferenceEndpointAction.java

@@ -113,13 +113,19 @@ public Response(boolean acknowledged, Set<String> pipelineIds) {
 
         public Response(StreamInput in) throws IOException {
             super(in);
-            pipelineIds = in.readCollectionAsSet(StreamInput::readString);
+            if (in.getTransportVersion().onOrAfter(TransportVersions.ML_INFERENCE_ENHANCE_DELETE_ENDPOINT)) {
+                pipelineIds = in.readCollectionAsSet(StreamInput::readString);
+            } else {
+                pipelineIds = Set.of();
+            }
         }
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             super.writeTo(out);
-            out.writeCollection(pipelineIds, StreamOutput::writeString);
+            if (out.getTransportVersion().onOrAfter(TransportVersions.ML_INFERENCE_ENHANCE_DELETE_ENDPOINT)) {
+                out.writeCollection(pipelineIds, StreamOutput::writeString);
+            }
         }
 
         @Override