more elementary command-line, following lib/Tools/components;

--- a/src/Pure/System/components.scala	Mon Jan 23 20:23:48 2023 +0100
+++ b/src/Pure/System/components.scala	Mon Jan 23 20:27:46 2023 +0100
@@ -51,7 +51,8 @@
   def unpack(dir: Path, archive: Path, progress: Progress = new Progress): String = {
     val name = Archive.get_name(archive.file_name)
     progress.echo("Unpacking " + name)
-    Isabelle_System.extract(archive, dir)
+    Isabelle_System.bash(
+      "tar -C " + File.bash_path(dir) + " -x -z -f " + File.bash_path(archive)).check
     name
   }