BUILDTOOLS-676: Downgrade Maven compiler version

By: md_5 <git@md-5.net>

paper-server/pom.xml

@@ -475,7 +475,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.13.0</version>
+                <version>3.12.1</version>
                 <configuration>
                     <!-- we use the Eclipse compiler as it doesn't need a JDK -->
                     <compilerId>eclipse</compilerId>
@@ -486,7 +486,7 @@
                     <dependency>
                         <groupId>org.codehaus.plexus</groupId>
                         <artifactId>plexus-compiler-eclipse</artifactId>
-                        <version>2.15.0</version>
+                        <version>2.14.2</version>
                     </dependency>
                 </dependencies>
             </plugin>