[8.x] Add version prefix to Inference Service API path (#117696)

* Add version prefix to Inference Service API path

* Update docs/changelog/117696.yaml

Author: demjened

docs/changelog/117696.yaml

@@ -0,0 +1,5 @@
+pr: 117696
+summary: "[8.x] Add version prefix to Inference Service API path"
+area: Inference
+type: enhancement
+issues: []

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceServiceSparseEmbeddingsModel.java

@@ -108,6 +108,6 @@ private URI createUri() throws URISyntaxException {
             default -> throw new IllegalArgumentException("Unsupported model for EIS [" + modelId + "]");
         }
 
-        return new URI(elasticInferenceServiceComponents().eisGatewayUrl() + "/sparse-text-embedding/" + modelIdUriPath);
+        return new URI(elasticInferenceServiceComponents().eisGatewayUrl() + "/api/v1/sparse-text-embedding/" + modelIdUriPath);
     }
 }