Update compile plugin to support Java 21

Author: tastybento

pom.xml

@@ -183,7 +183,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.7.0</version>
+                <version>3.8.1</version>
                 <configuration>
                     <release>${java.version}</release>
                 </configuration>