(improvement)(common) Upgraded langchain4j to version 0.31. (#1174)

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

@@ -0,0 +1,15 @@
+package dev.langchain4j.model.embedding;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class EmbeddingModelConfig {
+
+    @Bean
+    @ConditionalOnMissingBean
+    public EmbeddingModel embeddingModel() {
+        return new BgeSmallZhEmbeddingModel();
+    }
+}