fix：加载模型到内存时内存泄露bug (#1465)

* fix existSegment bug which embedding search not has min-score,so that it will return true.

common/src/main/java/dev/langchain4j/model/embedding/S2OnnxEmbeddingModel.java

@@ -19,7 +19,7 @@ import java.nio.file.Paths;
  */
 public class S2OnnxEmbeddingModel extends AbstractInProcessEmbeddingModel {
 
-    private final OnnxBertBiEncoder model;
+    private static OnnxBertBiEncoder model = null;
 
     /**
      * @param pathToModel The path to the .onnx model file (e.g., "/home/me/model.onnx").
@@ -33,7 +33,9 @@ public class S2OnnxEmbeddingModel extends AbstractInProcessEmbeddingModel {
                 throw new RuntimeException(e);
             }
         }
-        model = loadFromFileSystem(Paths.get(pathToModel), resource);
+        if (model == null) {
+            model = loadFromFileSystem(Paths.get(pathToModel), resource);
+        }
     }
 
     /**

headless/chat/src/main/java/com/tencent/supersonic/headless/chat/corrector/TimeCorrector.java

@@ -108,5 +108,4 @@ public class TimeCorrector extends BaseSemanticCorrector {
             semanticParseInfo.getSqlInfo().setCorrectedS2SQL(correctS2SQL);
         }
     }
-
-}
+}