Lint Python notebooks with ruff. (#12677)

The new ruff version fixed the blocking bugs, and I was able to fairly
easily us to a passing state: ruff fixed some issues on its own, I fixed
a handful by hand, and I added a list of narrowly-targeted exclusions
for files that are currently failing ruff rules that we probably should
look into eventually.

I went pretty lenient on the docs / cookbooks rules, allowing dead code
and such things. Perhaps in the future we may want to tighten the rules
further, but this is already a good set of checks that found real issues
and will prevent them going forward.

cookbook/gymnasium_agent_simulation.ipynb

@@ -27,16 +27,11 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "import gymnasium as gym\n",
-    "import inspect\n",
     "import tenacity\n",
     "\n",
-    "from langchain.chat_models import ChatOpenAI\n",
     "from langchain.schema import (\n",
-    "    AIMessage,\n",
     "    HumanMessage,\n",
     "    SystemMessage,\n",
-    "    BaseMessage,\n",
     ")\n",
     "from langchain.output_parsers import RegexParser"
    ]
@@ -131,7 +126,7 @@
     "            ):\n",
     "                with attempt:\n",
     "                    action = self._act()\n",
-    "        except tenacity.RetryError as e:\n",
+    "        except tenacity.RetryError:\n",
     "            action = self.random_action()\n",
     "        return action"
    ]