[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

docs/nb.ipynb

@@ -15,8 +15,10 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from dargs.sphinx import _test_argument\n",
+    "from __future__ import annotations\n",
+    "\n",
     "from dargs.notebook import JSON\n",
+    "from dargs.sphinx import _test_argument\n",
     "\n",
     "jstr = \"\"\"\n",
     "{\n",