ci: fix S3 artifact handoff

[yanghang8612]

Summary

• route upload-to-s3 specifically to the self-hosted for-linux runner
• upgrade actions/upload-artifact from v4 to the Node.js 24-based v6
• upgrade actions/download-artifact from v4 to the Node.js 24-based v7

Root cause

The S3 job used only [self-hosted, Linux], which also matched the Emscripten runner. Run 29890009976 was therefore assigned to runner ems instead of runner linux.

The first artifact download reached the Azure Blob redirect but failed to download and extract the artifact after five retries. The upload step was never reached, so this failure was unrelated to S3 credentials.

The same run also warned that actions/upload-artifact@v4 and actions/download-artifact@v4 target deprecated Node.js 20. The runner forced those actions onto Node.js 24, producing additional punycode and Buffer() deprecation warnings.

Impact

• the S3 job can no longer be scheduled on the ems runner
• artifact actions run natively on Node.js 24 without the Node.js 20 compatibility warnings
• artifact names, paths, packaging, and S3 destinations are unchanged

Validation

• actionlint passed with the repository's known custom for-linux runner label allowed
• YAML runner and action-version checks passed
• git diff --check passed
• the selected self-hosted Linux runner version observed in the previous run is 2.335.1, newer than the 2.327.1 minimum required by the Node.js 24 artifact actions

Failed production run: https://github.com/tronprotocol/solidity/actions/runs/29890009976

[github-actions]

Thank you for your contribution to the Solidity compiler! A team member will follow up shortly.

If you haven't read our contributing guidelines and our review checklist before, please do it now, this makes the reviewing process and accepting your contribution smoother.

If you have any questions or need our help, feel free to post them in the PR or talk to us directly on the #solidity-dev channel on Matrix.