ci: bump actions/checkout to v7

[Steel-tech]

The first CI run on main emitted a deprecation annotation on both test jobs:

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4

Bumps to actions/checkout@v7. Verified against the upstream repo rather than assumed — v5.1.0, v6.1.0, and v7.0.1 all declare using: node24, so any would clear the warning; v7.0.1 is the current stable major.

Expected result: the same three green jobs with no deprecation annotation.

Post-Deploy Monitoring & Validation

Watch this PR's run for the absence of the Node 20 annotation, with all three jobs still green and 91 tests per runner. No runtime or production impact — CI configuration only.

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Summary by CodeRabbit

• Chores
  • Updated automated build and validation workflows to use the latest repository checkout action.
  • Improved workflow credential handling to reduce unnecessary access during automated runs.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 2c1c6232-7971-414f-821b-550eff58e74a

📥 Commits

Reviewing files that changed from the base of the PR and between 737b05b and 0a6dd79.

📒 Files selected for processing (1)

• .github/workflows/ci.yml

🚧 Files skipped from review as they are similar to previous changes (1)

• .github/workflows/ci.yml

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📝 Walkthrough

Walkthrough

The CI workflow updates the checkout action from actions/checkout@v4 to actions/checkout@v7 and disables persisted Git credentials in the test and clippy jobs.

Changes

CI checkout action update

Layer / File(s)	Summary
Update CI checkout actions .github/workflows/ci.yml	The test and clippy jobs now use actions/checkout@v7 instead of @v4. Both jobs disable persisted Git credentials.

Estimated code review effort: 1 (Trivial) | ~2 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: updating actions/checkout to version 7 in CI.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch ci/checkout-v7

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_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In @.github/workflows/ci.yml:
- Line 29: Update both actions/checkout@v7 steps in the CI workflow to set
persist-credentials to false, unless either checkout is followed by a step that
explicitly requires authenticated Git operations.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 8fe47d90-4467-43ae-8ef2-91ed21563073

📥 Commits

Reviewing files that changed from the base of the PR and between ab4c716 and 737b05b.

📒 Files selected for processing (1)

• .github/workflows/ci.yml