Bump actions/upload-artifact from 4 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/release-publish.yml

@@ -237,14 +237,14 @@ jobs:
           echo "DEB_FILE=nsed-orchestrator_${VERSION}_${ARCH}.deb" >> "$GITHUB_ENV"
 
       - name: Upload tarball artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: binary-${{ matrix.target }}
           path: ${{ env.ARCHIVE }}
 
       - name: Upload .deb artifact
         if: matrix.deb_arch != ''
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: deb-${{ matrix.deb_arch }}
           path: ${{ env.DEB_FILE }}
@@ -255,7 +255,7 @@ jobs:
           echo "${{ steps.sha.outputs.sha256 }}" > "${{ matrix.target }}.sha256"
 
       - name: Upload SHA256 file
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: sha256-file-${{ matrix.target }}
           path: ${{ matrix.target }}.sha256