build(deps): bump AtomiCloud/actions.setup-nix from 2 to 3

[dependabot]

Bumps AtomiCloud/actions.setup-nix from 2 to 3.

Release notes

Sourced from AtomiCloud/actions.setup-nix's releases.

v3.0.0

3.0.0 (2026-06-10)

✨ Features ✨

• breaking: release new major for upgraded sub-actions (8390abf)
• breaking: upgrade sub-actions to latest major versions (#13) (0d56956)
• upgrade sub-actions to latest versions (79a522c)

v2.6.0

2.6.0 (2025-07-16)

🐛 Bug Fixes 🐛

• remove attic-related CI (ebc4b32)

✨ Features ✨

• change default of attic to false (4407a27)
• change default of attic to false (#12) (e2ff764)

v2.5.1

2.5.1 (2025-06-25)

🐛 Bug Fixes 🐛

• correct use attic substituters (e463bb9)

v2.5.0

2.5.0 (2025-06-17)

🐛 Bug Fixes 🐛

• incorrect workflow wait (7672a6c)
• use non-namespacelabs version for macos (d385c6f)

✨ Features ✨

• allow using attic token (fcc736d)
• cache nix shells (234adf0)
• only push shells on tag release (8374be1)
• use substituters directly (302cad0)

v2.4.0

... (truncated)

Changelog

Sourced from AtomiCloud/actions.setup-nix's changelog.

3.1.2 (2026-06-12)

🐛 Bug Fixes 🐛

• re-own cache tree at push time, not only at setup (61e3a58)
• re-own cache tree at push time, not only at setup (#16) (acde4f0)

3.1.1 (2026-06-11)

🐛 Bug Fixes 🐛

• own darwin cache path so the post-push hook can write (1676771)
• own darwin cache path so the post-push hook can write (#15) (1b9e41f)

3.1.0 (2026-06-11)

✨ Features ✨

• implement macOS Namespace file:// binary cache + auto push hook (01336a1)
• support namespacelabs cache on macOS via file:// binary cache (d0109c8)
• support namespacelabs cache on macOS via file:// binary cache (#14) (5f5ff37)

[Unreleased]

✨ Features ✨

• macOS Namespace cache: namespacelabs: 'true' now works on macOS runners. Because the APFS root volume is sealed (no /nix mount), the action persists a local file:// binary cache on a Namespace cache volume and pushes realized devShell closures back at end of job via an automatic post hook. This supersedes the previous "use non-namespacelabs version for macos" guidance — macOS callers can now use namespacelabs: 'true' with the standard cache labels. See the README for runner labels and operational semantics.

3.0.0 (2026-06-10)

✨ Features ✨

• breaking: release new major for upgraded sub-actions (8390abf)
• breaking: upgrade sub-actions to latest major versions (#13) (0d56956)
• upgrade sub-actions to latest versions (79a522c)

2.6.0 (2025-07-16)

🐛 Bug Fixes 🐛

... (truncated)

Commits

• de24d56 release: 3.1.2
• acde4f0 fix: re-own cache tree at push time, not only at setup (#16)
• 61e3a58 fix: re-own cache tree at push time, not only at setup
• 23caba5 release: 3.1.1
• 1b9e41f fix: own darwin cache path so the post-push hook can write (#15)
• 1676771 fix: own darwin cache path so the post-push hook can write
• 6d6a222 release: 3.1.0
• 5f5ff37 feat: support namespacelabs cache on macOS via file:// binary cache (#14)
• 01336a1 feat: implement macOS Namespace file:// binary cache + auto push hook
• d0109c8 feat: support namespacelabs cache on macOS via file:// binary cache
• Additional commits viewable in compare view