ci: upgrade GitHub Actions for Node.js 24 compatibility

[ko3n1g]

Summary

Upgrades all GitHub Actions to versions compatible with the Node.js 24 runtime, which GitHub is rolling out as the new runner default.

Action upgrades:

• actions/checkout: any version → v6
• actions/upload-artifact: any version → v6
• actions/download-artifact: any version → v7
• actions/github-script: any version → v8
• actions/setup-python: any version → v6

Mirrors: NVIDIA/Megatron-LM@1d5e68b

Test plan

• Verify CI pipelines pass after merge

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR performs a mechanical, repo-wide upgrade of five GitHub Actions to versions that run on the Node.js 24 runtime (node24), mirroring an identical change already applied to NVIDIA/Megatron-LM. All upgrades are internally consistent: actions/checkout@v6, actions/upload-artifact@v6, actions/download-artifact@v7, actions/github-script@v8, and actions/setup-python@v6 are applied uniformly across every workflow file that referenced an older version.

• Version pairing is correct – upload-artifact@v6 and download-artifact@v7 share the same artifact storage backend generation and are compatible with each other.
• Self-hosted runner requirement – actions/upload-artifact@v6 (and the other Node.js 24 actions) require Actions Runner ≥ 2.327.1. The self-hosted-nemo runner in _build_container.yml and the custom GPU/CPU runners in cicd-main.yml must be at or above that version before this change takes effect; GitHub-hosted ubuntu-latest runners satisfy this automatically.
• No behavioral changes – the upgrades are purely runtime/engine changes; no action inputs, outputs, or workflow logic was altered.

Confidence Score: 5/5

• Safe to merge; changes are mechanical version bumps with no logic alterations and a proven mirror in Megatron-LM.
• All five action upgrades are consistent and correct across every file. The version pairing (upload-artifact v6 / download-artifact v7) is intentional and validated by the referenced upstream commit. The only consideration is ensuring self-hosted runners are at the required minimum version, which is an operational pre-check rather than a code defect. No workflow logic, inputs, or outputs were changed.
• Confirm that self-hosted-nemo (used in _build_container.yml) and the custom GPU/CPU runners in cicd-main.yml are running Actions Runner ≥ 2.327.1 before merging.

Important Files Changed

Filename	Overview
.github/actions/test-template/action.yml	Upgrades actions/checkout from v2 → v6 and actions/upload-artifact from v4 → v6 for Node.js 24 compatibility.
.github/workflows/_build_container.yml	Upgrades actions/checkout from v4 → v6. This workflow runs on the self-hosted self-hosted-nemo runner, which must be at Actions Runner v2.327.1+ for the Node.js 24-based actions to work.
.github/workflows/cicd-approve-test-queue.yml	Upgrades actions/checkout from v4 → v6 and actions/setup-python from v5 → v6. Runs on ubuntu-latest (GitHub-hosted) so runner version requirement is automatically satisfied.
.github/workflows/cicd-main.yml	Comprehensive upgrade of actions/checkout (v4→v6), actions/upload-artifact (v4→v6), actions/download-artifact (v4→v7), and actions/github-script (v6→v8) throughout the main CI/CD pipeline. Version pairing of upload-artifact@v6 with download-artifact@v7 is consistent with the referenced Megatron-LM mirror commit.
.github/workflows/code-linting.yml	Upgrades actions/checkout from v4 → v6. Runs on ubuntu-latest so no self-hosted runner concern.

Sequence Diagram

sequenceDiagram
    participant PR as Pull Request Push
    participant PF as pre-flight
    participant BC as _build_container<br/>(checkout@v6)
    participant UT as cicd-unit-tests<br/>(checkout@v6)
    participant UA as upload-artifact@v6
    participant NT as cicd-nightly-tests<br/>(checkout@v6)
    participant DA as download-artifact@v7
    participant PT as publish-test-results
    participant NC as Nemo_CICD_Test<br/>(checkout@v6, github-script@v8)
    participant CV as Coverage<br/>(checkout@v6)

    PR->>PF: trigger
    PF->>BC: dispatch (self-hosted-nemo runner)
    BC->>UT: image ready
    UT->>UA: upload test results
    BC->>NT: image ready (schedule only)
    NT->>UA: upload test results
    UA->>DA: artifacts stored
    DA->>PT: download & publish
    UT->>NC: status
    NC->>CV: trigger coverage aggregation
    CV->>DA: download coverage artifacts
    CV->>UA: upload aggregated coverage

Loading

_{Reviews (1): Last reviewed commit: "ci: upgrade GitHub Actions for Node.js 2..." | Re-trigger Greptile}

[greptile-apps]

Self-hosted runner version prerequisite

actions/upload-artifact@v6 (and the other Node.js 24-based actions) require a minimum Actions Runner version of 2.327.1. This workflow runs on self-hosted-nemo (a self-hosted runner), so before or alongside this merge you'll want to confirm that runner has been updated. GitHub-hosted runners on ubuntu-latest pick this up automatically, but self-hosted ones don't.

The same applies to the custom GPU runners (${{ needs.pre-flight.outputs.runner_prefix }}-gpu-x2, linux-amd64-cpu16) used in cicd-main.yml. If those runners are below 2.327.1, the jobs will fail with a node24 runtime error at startup rather than a meaningful test failure.

[github-actions]

Test Results

   48 files  ±0     98 suites  ±0   1m 18s ⏱️ -1s
1 012 tests ±0  1 012 ✅ ±0  0 💤 ±0  0 ❌ ±0 
2 255 runs  ±0  2 255 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 406bb7b. ± Comparison against base commit 8a44b09.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!