github-actions(deps): bump actions/download-artifact from 5 to 6 (#127)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build.yml

@@ -54,7 +54,7 @@ jobs:
         fetch-depth: 0
 
     - name: Download coverage report
-      uses: actions/download-artifact@v5
+      uses: actions/download-artifact@v6
       with:
         name: coverage-report
         path: backend