change: 移除数据库的实例工厂.

src/main/java/com/serliunx/ddns/core/factory/AbstractInstanceFactory.java

@@ -14,7 +14,6 @@ import static com.serliunx.ddns.util.InstanceUtils.validateInstance;
 /**
  * 实例工厂抽象实现, 定义通用逻辑及实例存储.
  * @see FileInstanceFactory
- * @see DatabaseInstanceFactory
  * @author <a href="mailto:serliunx@yeah.net">SerLiunx</a>
  * @version 1.0.0
  * @since 2024/5/15

src/main/java/com/serliunx/ddns/core/factory/DatabaseInstanceFactory.java

@@ -1,20 +0,0 @@
-package com.serliunx.ddns.core.factory;
-
-import com.serliunx.ddns.core.instance.Instance;
-
-import java.util.Collections;
-import java.util.Set;
-
-/**
- * 数据库实例工厂
- * @author <a href="mailto:serliunx@yeah.net">SerLiunx</a>
- * @version 1.0.0
- * @since 2024/5/15
- */
-public abstract class DatabaseInstanceFactory extends AbstractInstanceFactory {
-
-    @Override
-    protected Set<Instance> load() {
-        return Collections.emptySet();
-    }
-}