(#2) Upgrade CI and release workflows to Node 24-compatible GitHub Actions

[vjanelle]

Motivation

• The CI and release workflows were using action versions that run on Node.js 20, which is being deprecated and can cause workflows to fail when GitHub defaults to Node.js 24.
• The change aims to opt the workflows into Node.js 24 now and move to action major versions that support the newer runtime.

Description

• Updated action versions in .github/workflows/ci.yml and .github/workflows/release.yml: actions/checkout@v4 → actions/checkout@v5, actions/setup-go@v5 → actions/setup-go@v6, actions/upload-artifact@v4 → actions/upload-artifact@v5, and actions/download-artifact@v4 → actions/download-artifact@v5 (release workflow).
• Added a workflow-level environment variable FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true" to both CI and Release workflows to opt in to the Node.js 24 runtime.
• No changes were made to job logic besides updating action versions and adding the opt-in environment variable.

Testing

• Parsed all workflow YAML files with ruby -ryaml -e 'Dir[".github/workflows/*.yml"].each{|f| YAML.load_file(f); puts "ok #{f}" }' and all files loaded successfully.
• Attempted a Python yaml.safe_load check but it failed due to PyYAML not being installed in the environment, so that validation was not run there.

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Codex Task