fix: Filter 'app list' output by executable (#1783)

Co-authored-by: Igor <foreverigor@users.noreply.github.com>

src/main/java/dev/jbang/cli/App.java

@@ -322,6 +322,7 @@ public AppOut(Path file) {
  private static List<AppOut> listCommandFiles() {
  try (Stream<Path> files = Files.list(Settings.getConfigBinDir())) {
  return files
+ .filter(Files::isExecutable)
  .sorted()
  .map(AppOut::new)
  .filter(distinctByKey(AppOut::getName))