Bump actions/download-artifact from 4 to 8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v4...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -56,7 +56,7 @@ jobs:
         if: github.ref == 'refs/heads/main' || github.ref == 'refs/heads/go'
         steps:
             - name: Download binary
-              uses: actions/download-artifact@v4
+              uses: actions/download-artifact@v8
               with:
                   name: pkgstatsd
             - name: Deploy