Bump flask from 2.1.1 to 2.1.2

Bumps [flask](https://github.com/pallets/flask) from 2.1.1 to 2.1.2.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](https://github.com/pallets/flask/compare/2.1.1...2.1.2

)

---
updated-dependencies:
- dependency-name: flask
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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