Update enforcer-rules smoke test to use JBoss Parent 39

This version uses a maven-compiler-plugin version that is available on
Maven Central by default so we are not dependent of JBoss Nexus.

(cherry picked from commit 6dceb8b)

independent-projects/enforcer-rules/src/it/smoketest/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>org.jboss</groupId>
         <artifactId>jboss-parent</artifactId>
-        <version>38</version>
+        <version>39</version>
     </parent>
 
     <groupId>io.quarkus</groupId>