increase timeout for starting feature to fix Jenkins build

some cleanup, use newest launcher
diff --git a/sling-maven-plugin/pom.xml b/sling-maven-plugin/pom.xml
index e976a53..130db05 100644
--- a/sling-maven-plugin/pom.xml
+++ b/sling-maven-plugin/pom.xml
@@ -48,6 +48,7 @@
         <sling.java.version>8</sling.java.version>
         <mavenVersion>3.3.1</mavenVersion><!-- minimum target Maven version this plugin is compatible with -->
         <maven.compiler.target>${sling.java.version}</maven.compiler.target><!-- also set target next to release due to https://issues.apache.org/jira/browse/MPLUGIN-404 -->
+        <starter-its.startTimeoutSeconds>60</starter-its.startTimeoutSeconds><!-- the time in seconds to wait for Sling Starter Feature to be started for the ITs -->
     </properties>
 
     <build>
@@ -110,6 +111,8 @@
                 <artifactId>feature-launcher-maven-plugin</artifactId>
                 <version>0.1.2</version>
                 <configuration>
+                    <!-- newer versions don't work due to https://issues.apache.org/jira/browse/SLING-11158 -->
+                    <featureLauncherVersion>1.1.26</featureLauncherVersion>
                     <launches>
                         <launch>
                             <id>sling-starter-oak-tar</id>
diff --git a/sling-maven-plugin/src/main/java/org/apache/sling/maven/bundlesupport/GenerateAdapterMetadataMojo.java b/sling-maven-plugin/src/main/java/org/apache/sling/maven/bundlesupport/GenerateAdapterMetadataMojo.java
index 8b36663..0a5a72d 100644
--- a/sling-maven-plugin/src/main/java/org/apache/sling/maven/bundlesupport/GenerateAdapterMetadataMojo.java
+++ b/sling-maven-plugin/src/main/java/org/apache/sling/maven/bundlesupport/GenerateAdapterMetadataMojo.java
@@ -19,18 +19,13 @@
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.net.URLClassLoader;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.Map;
 
 import javax.json.Json;
 import javax.json.JsonException;
 import javax.json.JsonWriter;
 
-import org.apache.maven.model.Resource;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
@@ -49,8 +44,6 @@
 import io.github.classgraph.AnnotationParameterValue;
 import io.github.classgraph.AnnotationParameterValueList;
 import io.github.classgraph.ClassGraph;
-import io.github.classgraph.ClassGraph.ClasspathElementFilter;
-import io.github.classgraph.ClassGraph.ClasspathElementURLFilter;
 import io.github.classgraph.ClassInfo;
 import io.github.classgraph.ClassInfoList;
 import io.github.classgraph.ScanResult;