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/cache: any version → v5
• astral-sh/setup-uv: any version → v7

Mirrors: NVIDIA/Megatron-LM@1d5e68b

Test plan

• Verify CI pipelines pass after merge

🤖 Generated with Claude Code

[github-actions]

All contributors have signed the DCO ✍️ ✅
_{Posted by the DCO Assistant Lite bot.}

[greptile-apps]

Greptile Summary

This PR upgrades all GitHub Actions across six workflow files to versions compatible with the Node.js 24 runner runtime. The changes are purely mechanical version bumps — no workflow logic, step ordering, or configuration values are altered.

Changes across all workflows:

• actions/checkout: v2/v4 → v6
• astral-sh/setup-uv: v5/v6 → v7
• actions/cache: v4 → v5 (build-notebooks.yml)
• actions/upload-artifact: v4 → v6 (build-notebooks.yml)
• actions/download-artifact: v5 → v7 (build-docs.yml, pack-tutorials.yml)

The upgrade is consistent across all jobs and mirrors a validated pattern from the NVIDIA/Megatron-LM repository. No issues were found.

Confidence Score: 5/5

• Safe to merge — all changes are straightforward version bumps with no logic alterations.
• All changes are mechanical action version upgrades targeting Node.js 24 compatibility. The upgrade targets are explicitly documented in the PR description, mirror a validated upstream commit, and no issues were found across any of the six affected files.
• No files require special attention.

Important Files Changed

Filename	Overview
.github/workflows/build-docs.yml	Upgrades actions/checkout v2→v6, astral-sh/setup-uv v6→v7, and actions/download-artifact v5→v7
.github/workflows/build-notebooks.yml	Upgrades actions/checkout v2→v6, astral-sh/setup-uv v6→v7, actions/cache v4→v5, and actions/upload-artifact v4→v6
.github/workflows/check-colab-notebooks.yml	Upgrades actions/checkout v4→v6 and astral-sh/setup-uv v5→v7
.github/workflows/ci.yml	Upgrades actions/checkout v4→v6 and astral-sh/setup-uv v5→v7 across all seven jobs in the workflow
.github/workflows/health-checks.yml	Upgrades actions/checkout v4→v6 and astral-sh/setup-uv v5→v7
.github/workflows/pack-tutorials.yml	Upgrades actions/download-artifact v5→v7

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[Push / PR trigger] --> B[ci.yml]
    A --> C[check-colab-notebooks.yml]
    A --> D[health-checks.yml]

    B --> E["actions/checkout@v6\nastral-sh/setup-uv@v7"]
    C --> F["actions/checkout@v6\nastral-sh/setup-uv@v7"]
    D --> G["actions/checkout@v6\nastral-sh/setup-uv@v7"]

    A --> H[build-notebooks.yml]
    H --> I["actions/checkout@v6\nastral-sh/setup-uv@v7\nactions/cache@v5"]
    I --> J["actions/upload-artifact@v6\n(artifacts: notebooks)"]

    J --> K[build-docs.yml]
    K --> L["actions/checkout@v6\nastral-sh/setup-uv@v7\nactions/download-artifact@v7"]

    J --> M[pack-tutorials.yml]
    M --> N["actions/download-artifact@v7"]

Loading

_{Reviews (3): Last reviewed commit: "Merge branch 'main' into ko3n1g/upgrade-..." | Re-trigger Greptile}

[andreatgretel]

Thanks for addressing these upgrades! I checked for breaking changes across all the version bumps and everything looks safe - inputs and defaults are unchanged, it's essentially just the node20 → node24 runtime switch. We should keep an eye on the pipelines after merging, but I don't expect issues.

Would you mind also including these in the PR? They're also still on node20:

• actions/cache@v4 → @v5 in build-notebooks.yml
• astral-sh/setup-uv@v5 → @v7 in ci.yml, check-colab-notebooks.yml, health-checks.yml
• astral-sh/setup-uv@v6 → @v7 in build-docs.yml, build-notebooks.yml

I verified none of the workflows use any of the inputs that were removed/renamed between setup-uv v5 and v7 (pyproject-file, uv-file, server-url), so it should be a clean bump.

Once the changes are in, we can trigger health-checks, build-notebooks, and check-colab-notebooks manually on the PR branch to validate before merging - those are safe to run without side effects. ci.yml already runs on the PR. The remaining two (build-docs, pack-tutorials) touch deployments/releases, but they use the same actions already covered by the other workflows.

Two other actions (softprops/action-gh-release@v2, contributor-assistant/github-action) are also on node20 but don't have node24 releases yet - we'll track those separately.

Also a small note: the PR description mentions actions/github-script and actions/setup-python upgrades, but neither is used in this repo - looks like carry-over from the Megatron-LM commit.

[ko3n1g]

Triggered the three safe-to-run workflows on the PR branch as suggested:

• Health Checks: https://github.com/NVIDIA-NeMo/DataDesigner/actions/runs/23747191512
• Build notebooks: https://github.com/NVIDIA-NeMo/DataDesigner/actions/runs/23747193681
• Check Colab notebooks: https://github.com/NVIDIA-NeMo/DataDesigner/actions/runs/23747195627

[ko3n1g]

I have read the DCO document and I hereby sign the DCO.