Renovate[bot]: Update actions/setup-node action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/setup-node	action	major	v3 -> v4

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Pre-merge checks

• [x] Make sure the GitHub Actions tests are passing.

• [x] Run bin/compare-build-branch.sh locally on this branch and confirm that this PR is not causing unexpected changes to the build. Requirements to run this script: grunt build and nvm.

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Release Notes

actions/setup-node (actions/setup-node)

### [`v4`](https://togithub.com/actions/setup-node/compare/v3...v4) [Compare Source](https://togithub.com/actions/setup-node/compare/v3...v4)

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• [ ] If you want to rebase/retry this PR, check this box

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[mattyrob]

bin/compare-build-branch.sh check is irrelevant here as this change only impacts automated testing.