ci: overlap Rust and Nix setup

[robjtede]

Run Rust and Cargo tool setup in parallel with Nix installation and nicknovitski/nix-develop. Wait for both before running checks.

Summary by CodeRabbit

• Chores
  • CI setup now runs Rust toolchain installation and Nix devshell setup in parallel before tests, reducing setup time.

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-10-08 01:44 UTC

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 9a774759-57d0-43bd-b34c-cb6ed82f6fea

📥 Commits

Reviewing files that changed from the base of the PR and between aac29eb and 9b20bde.

📒 Files selected for processing (1)

• .github/workflows/ci.yml

Included review availability: This review used your included allowance. Your plan provides up to 1 included review per hour; 0 remain after this review.

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📝 Walkthrough

Walkthrough

The CI workflow runs Rust toolchain setup and devshell entry in the background. It waits for both before continuing to the existing MSRV workaround and test steps.

Changes

CI setup

Layer / File(s)	Summary
DevShell and Rust setup .github/workflows/ci.yml	Rust toolchain setup and devshell entry now run in the background. The workflow waits for both steps before continuing.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~8 minutes

Change: Refactor

Merge Risk: ⚪ Minimal · up to 9b20b

No actionable CI setup risk is established by the reviewed changes; the workflow can merge subject to normal checks.

🚥 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: running Rust and Nix setup steps in parallel during CI.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
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.

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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