Bump the production-dependencies group with 3 updates

Bumps the production-dependencies group with 3 updates: [flask](https://github.com/pallets/flask), [ghapi](https://github.com/fastai/ghapi) and [gunicorn](https://github.com/benoitc/gunicorn).


Updates `flask` from 2.3.2 to 3.0.0
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@2.3.2...3.0.0)

Updates `ghapi` from 1.0.3 to 1.0.4
- [Release notes](https://github.com/fastai/ghapi/releases)
- [Changelog](https://github.com/fastai/ghapi/blob/master/CHANGELOG.md)
- [Commits](https://github.com/fastai/ghapi/commits)

Updates `gunicorn` from 20.1.0 to 21.2.0
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@20.1.0...21.2.0)

---
updated-dependencies:
- dependency-name: flask
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: production-dependencies
- dependency-name: ghapi
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: production-dependencies
- dependency-name: gunicorn
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: production-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>