poetry: bump datamodel-code-generator from 0.26.1 to 0.28.5

Bumps [datamodel-code-generator](https://github.com/koxudaxi/datamodel-code-generator) from 0.26.1 to 0.28.5.
- [Release notes](https://github.com/koxudaxi/datamodel-code-generator/releases)
- [Commits](koxudaxi/datamodel-code-generator@0.26.1...0.28.5)

---
updated-dependencies:
- dependency-name: datamodel-code-generator
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]