Upgrade to Maven 4.0.0-alpha-9 (#27)

Author: gnodet

pom.xml

@@ -55,7 +55,7 @@ limitations under the License.
     <dependency>
       <groupId>org.apache.maven</groupId>
       <artifactId>maven-xml-impl</artifactId>
-      <version>4.0.0-alpha-8</version>
+      <version>4.0.0-alpha-9</version>
       <exclusions>
         <exclusion>
           <groupId>org.eclipse.sisu</groupId>