chore(deps): bump flake.lock

[github-actions]

Automated changes by the update-flake-lock GitHub Action.

Flake lock file updates:

• Updated input 'zig2nix':
    'github:Cloudef/zig2nix/8f05359c82869155d2b8c03fe79ac2c381c9009f?narHash=sha256-Nbuq/dPrg19oTXnYSK4CXFpiRbt0/dZhTErA1my60CY%3D' (2024-12-07)
  → 'github:Cloudef/zig2nix/b21f647ed845f6f7ba9a6be6becccf608da777f9?narHash=sha256-ltvW4xhBPBS8yQ8nFICKjh6k7yTLsz98lLthy9MBdOQ%3D' (2024-12-14)

Running GitHub Actions on this PR

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To run GitHub Actions workflows on this PR, run:

git branch -D update_flake_lock_action
git fetch origin
git checkout update_flake_lock_action
git commit --amend --no-edit
git push origin update_flake_lock_action --force