build.yml: Enable provenance

[edolstra]

Motivation

Hopefully make it easier to map store paths from Sentry crash reports back to the exact build.

Context

Summary by CodeRabbit

• Chores
  • Updated build and test automation to enable Nix provenance consistently across major pipeline jobs.
  • Improves the uniformity of build metadata to support more traceable release artifacts.

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR adds extra-conf: extra-experimental-features = provenance to the determinate-nix-action step in seven CI jobs in build.yml. It also includes a whitespace-only line change at the start of src/nix/main.cc.

Changes

CI Provenance Config

Layer / File(s)	Summary
Enable provenance flag across CI jobs .github/workflows/build.yml	Adds extra-conf: extra-experimental-features = provenance to the determinate-nix-action step in the build, build_static, test, vm_tests_smoke, vm_tests_all, flake_regressions, and manual jobs.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Suggested reviewers: grahamc, cole-h

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: enabling provenance in build.yml.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch gha-enable-provenance

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

[github-actions]

🚀 Deployed on https://6a4fb0e0e6ce7b63e083b271--determinate-nix.netlify.app