chore: weekly flake.lock update

[caffeine-ci-generic-rw]

Automated changes by the update-flake-lock GitHub Action
as defined in .github/workflows/update-flake-lock-trial.yml
and run in: https://github.com/caffeinelabs/motoko/actions/runs/26699696873/attempts/1:

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/77d4132' (2026-05-24)
  → 'github:NixOS/nixpkgs/9396caa' (2026-05-30)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/1d634a9' (2026-05-09)
  → 'github:oxalica/rust-overlay/85570ef' (2026-05-30)

This PR is just to test if the above dependency bumps cause issues.
If checks fail, this PR remains open so we can investigate.
If all checks succeed this PR is automatically closed.

[github-actions]

Cursor AI review

👍 APPROVE — looks safe to merge

Category	Assessment	Details
Summary	✅	Automated weekly flake.lock trial bump: nixpkgs (77d4132 → 9396caa) and rust-overlay (1d634a9 → 85570ef); no compiler, RTS, or Motoko source changes.
Code Quality	✅	Standard lock-file pin update with consistent rev/narHash/lastModified fields; no new code.
Consistency	✅	Matches the existing update-flake-lock-trial.yml workflow and its configured inputs.
Correctness	✅	Lock entries are structurally valid; nixpkgs remains pinned to release-26.05.
Tests	✅	No Motoko test changes required; CI is the intended validation gate for this trial PR.
Changelog	✅	Build-infra-only change; no user-visible language, prelude, or CLI behavior change.

Verdict

Decision: APPROVE
Risk: Low
Reason: This is a routine, automated lock-file dependency refresh with CI as the safety check and no Motoko compiler or runtime source changes. I found no defects or regressions introduced by the diff relative to the base SHA.

---

Generated for commit 8359bb0

[github-actions]

Comparing from 6e25ac1 to 8359bb0:
The produced WebAssembly code seems to be completely unchanged.
In terms of gas, no changes are observed in 5 tests.
In terms of size, no changes are observed in 5 tests.

[github-actions]

CI looks good, this dependency bump would not cause problems, hence closing this trial PR.