Bump https://github.com/kynan/nbstripout from 0.8.0 to 0.9.1

Bumps [https://github.com/kynan/nbstripout](https://github.com/kynan/nbstripout) from 0.8.0 to 0.9.1. This release includes the previously tagged commit.
- [Release notes](https://github.com/kynan/nbstripout/releases)
- [Changelog](https://github.com/kynan/nbstripout/blob/main/CHANGELOG.md)
- [Commits](kynan/nbstripout@f42caea...34071b7)

---
updated-dependencies:
- dependency-name: https://github.com/kynan/nbstripout
  dependency-version: 0.9.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.pre-commit-config.yaml

@@ -3,7 +3,7 @@ default_install_hook_types: [pre-commit, pre-push]
 
 repos:
 - repo: https://github.com/kynan/nbstripout
-  rev: f42caeaf94f73a5ae54641b40a7d664cb4e03e40  # frozen: 0.8.0
+  rev: 34071b78c181af3bf5af955c1426466e096fc3db  # frozen: 0.9.1
   hooks:
     - id: nbstripout
       args: [--drop-empty-cells]