Fix a ZFS error during snapshot cleanup (#1001).

NEWS

@@ -1,5 +1,5 @@
 1.9.13.dev0
- * 
+ * #1001: Fix a ZFS error during snapshot cleanup.
 
 1.9.12
  * #1005: Fix the credential hooks to avoid using Python 3.12+ string features. Now borgmatic will

borgmatic/hooks/data_source/zfs.py

@@ -420,7 +420,7 @@ def remove_data_source_dumps(hook_config, config, borgmatic_runtime_directory, d
                     continue
 
         if not dry_run:
-            shutil.rmtree(snapshots_directory)
+            shutil.rmtree(snapshot_mount_path, ignore_errors=True)
 
     # Destroy snapshots.
     full_snapshot_names = get_all_snapshots(zfs_command)