[GR-14098] native-image-maven-plugin: Filter out non-jar dependencies from imagecp.

PullRequest: graal/3039

Author: olpaw

substratevm/src/native-image-maven-plugin/src/main/java/com/oracle/substratevm/NativeImageMojo.java

@@ -250,6 +250,10 @@ private String withExeSuffix(String basename) {
     }
 
     private void addClasspath(Artifact artifact) throws MojoExecutionException {
+        if (!"jar".equals(artifact.getType())) {
+            getLog().warn("Ignoring non-jar type ImageClasspath Entry " + artifact);
+            return;
+        }
         File artifactFile = artifact.getFile();
         if (artifactFile == null) {
             throw new MojoExecutionException("Missing jar-file for " + artifact + ". Ensure " + plugin.getArtifactId() + " runs in package phase.");