skip export completion if in algorithm

src/tree.py

@@ -316,7 +316,7 @@ class TreeWalker:
             meta_path = os.path.join(section_path, mfile)
             self.ensure_exercises_meta(meta_path, source)
             export = config.get("export", [])
-            if mfile not in export:
+            if mfile not in export and self.name != "algorithm":
                 export.append(mfile)
                 flag = True
                 config["export"] = export