ci: bump Actions off Node 20 runtime (#6)

[chtnnh]

Summary

• Bump actions/checkout / setup-node to v5 across workflows, composite action, and init --workflow
• Also bump Pages (upload-pages-artifact@v5 + include-hidden-files, deploy-pages@v5) so docs deploys stop warning
• Closes Bump GitHub Actions off deprecated Node 20 runtime (checkout/setup-node v4 → v5+) #6

Test plan

• CI green on this PR (no Node 20 action annotations)
• After merge, docs workflow deploy succeeds and .nojekyll is present

[cursor]

PR Summary

Low Risk
Dependency version bumps in workflow YAML only; the docs change is a deliberate fix for Pages artifact packaging.

Overview
Updates CI infrastructure to Actions v5 so workflows stop running on the deprecated Node 20 action runtime.

actions/checkout@v5 and actions/setup-node@v5 replace v4 in ci, docs, know-code, release, and umami-proxy, the composite action/action.yml, know-code init --workflow output (init.ts), docs (website/docs/ci.md), and the consumerWorkflowYaml test assertion.

For docs deploy, upload-pages-artifact and deploy-pages move to v5, with include-hidden-files: true on the upload step so dotfiles like .nojekyll are included (v4+ default behavior would omit them).

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