change to java 11

pom.xml

@@ -18,8 +18,8 @@
     </developers>
 
     <properties>
-        <maven.compiler.source>16</maven.compiler.source>
-        <maven.compiler.target>16</maven.compiler.target>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
 
         <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>