Bump packaging from 26.0 to 26.1 (#395)

Bumps [packaging](https://github.com/pypa/packaging) from 26.0 to 26.1.
- [Release notes](https://github.com/pypa/packaging/releases)
- [Changelog](https://github.com/pypa/packaging/blob/main/CHANGELOG.rst)
- [Commits](pypa/packaging@26.0...26.1)

---
updated-dependencies:
- dependency-name: packaging
  dependency-version: '26.1'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

backend/requirements.txt

@@ -28,7 +28,7 @@ jsonschema-specifications==2025.9.1
 MarkupSafe==3.0.3
 mccabe==0.7.0
 mysqlclient==2.2.8
-packaging==26.0
+packaging==26.1
 pipenv==2026.5.2
 platformdirs==4.9.6
 pluggy==1.6.0