[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/kynan/nbstripout: 0.7.1 → 0.8.1](kynan/nbstripout@0.7.1...0.8.1)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -31,7 +31,7 @@ repos:
     hooks:
       - id: flake8
   - repo: https://github.com/kynan/nbstripout
-    rev: 0.7.1
+    rev: 0.8.1
     hooks:
       - id: nbstripout
         args: [--extra-keys=metadata.kernelspec metadata.language_info.version]