build(deps): Bump actions/upload-artifact in /.github/actions/nix-build

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/actions/nix-build/action.yml

@@ -177,7 +177,7 @@ runs:
 
     - name: Upload build logs
       if: always()
-      uses: actions/upload-artifact@v5.0.0
+      uses: actions/upload-artifact@v6.0.0
       with:
         name: build-logs-${{inputs.system}}-${{github.job}}-${{strategy.job-index}}
         path: ".build/logs/*"