upgrade to java 17 for long-term support

Author: pmbittner

pom.xml

@@ -11,8 +11,8 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-        <maven.compiler.source>16</maven.compiler.source>
-        <maven.compiler.target>16</maven.compiler.target>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
     </properties>
 
     <build>