[BUG] ExtraPlugins might be loaded duplicated

[sperlingxx]

Describe the bug
(https://github.com/NVIDIA/spark-rapids/blob/branch-25.02/sql-plugin/src/main/scala/com/nvidia/spark/rapids/Plugin.scala#L356)

  private def getExtraPlugins: Seq[SparkPlugin] = {
    val resourceName = "spark-rapids-extra-plugins"
    val classLoader = RapidsPluginUtils.getClass.getClassLoader
    val resourceUrls = classLoader.getResources(resourceName)
    val resourceUrlArray = resourceUrls.asScala.toArray

    if (resourceUrlArray.isEmpty) {
      logDebug(s"Could not find file $resourceName in the classpath, not loading extra plugins")
      Seq.empty
    } else {
      val plugins = scala.collection.mutable.ListBuffer[SparkPlugin]()
      for (resourceUrl <- resourceUrlArray) {
        val source = scala.io.Source.fromURL(resourceUrl)
        val pluginClasses = source.getLines().toList
        source.close()
        plugins ++= loadExtensions(classOf[SparkPlugin], pluginClasses)
      }
      plugins.toSeq
    }
  }

The resourceUrls may contain duplicated urls for the same extra plugin to be loaded. And the a lot of extra plugins will go weirdly when being loaded multiple times.

[gerashegalov]

When does this happen? Do you specify the jars via --jars and extraClassPath at the same time?