[pre-commit.ci] pre-commit autoupdate (#382)

<!--pre-commit.ci start-->
updates:
- [github.com/nbQA-dev/nbQA: 1.8.7 →
1.9.1](nbQA-dev/nbQA@1.8.7...1.9.1)
<!--pre-commit.ci end-->

.pre-commit-config.yaml

@@ -61,7 +61,7 @@ repos:
         additional_dependencies: [".[toml]"]
 
   - repo: https://github.com/nbQA-dev/nbQA
-    rev: 1.8.7
+    rev: 1.9.1
     hooks:
       - id: nbqa-isort
         args: [--nbqa-mutate, --nbqa-dont-skip-bad-cells]