Remove samples from jar packaging (#226)

Remove build-helper-maven-plugin config that added samples/ as a source
directory, causing package-less sample classes to pollute classpath root.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: zhansheng.lzs

pom.xml

@@ -227,24 +227,6 @@
                     </execution>
                 </executions>
             </plugin>
-            <plugin>
-                <groupId>org.codehaus.mojo</groupId>
-                <artifactId>build-helper-maven-plugin</artifactId>
-                <version>3.4.0</version>
-                <executions>
-                    <execution>
-                        <phase>generate-sources</phase>
-                        <goals>
-                            <goal>add-source</goal>
-                        </goals>
-                        <configuration>
-                            <sources>
-                                <source>samples</source>
-                            </sources>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
         </plugins>
     </build>
 </project>