chore(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] <[email protected]>

Author: dependabot[bot]

.github/workflows/release.yml

@@ -100,7 +100,7 @@ jobs:
       # checkout will clobber downloaded artifacts
       # we have to download them again
       - name: 'Download all build artifacts'
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           path: artifacts
           pattern: power-server-*