Bump actions/download-artifact from 5.0.0 to 6.0.0 (open-telemetry#3719)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@634f93c...018cc2c)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/benchmark.yml

@@ -60,7 +60,7 @@ jobs:
           egress-policy: audit
 
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
-      - uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # main March 2025
+      - uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # main March 2025
         with:
           name: benchmark_results
           path: benchmarks