create: --list --dry-run output for directories, fixes #7209

Without the status being set no output was generated in
dry-run mode, confusing users about whether borg would back
up directories (in non-dry-run mode).

- == item not backed up just because of dry-run mode
x == item excluded

src/borg/archiver/create_cmd.py

@@ -442,8 +442,11 @@ class CreateMixIn:
                                         )
                                 self.print_file_status("x", path)
                             return
-                    if not recurse_excluded_dir and not dry_run:
-                        status = fso.process_dir_with_fd(path=path, fd=child_fd, st=st)
+                    if not recurse_excluded_dir:
+                        if not dry_run:
+                            status = fso.process_dir_with_fd(path=path, fd=child_fd, st=st)
+                        else:
+                            status = "-"
                     if recurse:
                         with backup_io("scandir"):
                             entries = helpers.scandir_inorder(path=path, fd=child_fd)