build(deps): bump actions/download-artifact from 4 to 6

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

Author: dependabot[bot]

.github/workflows/release.yml

@@ -84,7 +84,7 @@ jobs:
           echo "install task"
           go install github.com/go-task/task/v3/cmd/task@latest
       - name: "download checksums.txt"
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with: { name: checksums.txt, path: dist }
       - run: ./hack/scripts/gentap.sh
       - name: Build docs