Bump actions/download-artifact from 6 to 8 in /.github/workflows

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 6 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v6...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/docker-security.yml

@@ -205,13 +205,13 @@ jobs:
 
     steps:
       - name: 📥 Download Security Artifacts
-        uses: actions/download-artifact@v6
+        uses: actions/download-artifact@v8
         with:
           name: security-scan-results
           path: security-results/
 
       - name: 📥 Download Container SBOM
-        uses: actions/download-artifact@v6
+        uses: actions/download-artifact@v8
         with:
           name: container-sbom
           path: sbom-results/