fix: do not prune by default

apps/hiopy/_data_handler.py

@@ -14,7 +14,7 @@ class DataHandler:
         mi, ma, st = cell_slice.indices(shape["cell"])
         assert st == 1, "non-contiguous cell slices are not supported"
         self.t = t0
-        self.prune_offset = int(var.attrs.get("loco::num_retained_timesteps", 2))
+        self.prune_offset = var.attrs.get("loco::num_retained_timesteps", None)
         self.t_flushed = self.t
         chunks = {
             dim: chunk_size for dim, chunk_size in zip(var.attrs["_ARRAY_DIMENSIONS"], var.chunks)