修复当sheetName 不存在时，ExcelUtil.getReader方法不会释放文件问题

hutool-poi/src/test/java/org/dromara/hutool/poi/excel/IssueI8ZIQCTest.java

@@ -0,0 +1,10 @@
+package org.dromara.hutool.poi.excel;
+
+import org.junit.jupiter.api.Test;
+
+public class IssueI8ZIQCTest {
+	@Test
+	void readTest() {
+		final ExcelReader reader = ExcelUtil.getReader("d:/test/test3.xlsx", "aaa");
+	}
+}