Fixed compiler warnings on JDK21+

Author: alex268

pom.xml

@@ -137,7 +137,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.13.0</version>
+                <version>3.14.0</version>
                 <configuration>
                     <target>1.8</target>
                     <source>1.8</source>
@@ -146,6 +146,8 @@
                         <!-- Silence warning "No processor claimed any of these annotations". One of the
                         annotations that would trigger it is org.junit.jupiter.api.Test -->
                         <arg>-Xlint:-processing</arg>
+                        <!-- Silence warnning "source value 8 is obsolete and will be removed in a future release" -->
+                        <arg>-Xlint:-options</arg>
                     </compilerArgs>
                 </configuration>
             </plugin>