flake: update inputs (#370)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/30439d93eb8b19861ccbe3e581abf97bdc91b093?narHash=sha256-o8VBeCWHBxGd4kVMceIayf5GApqTavJbTa44Xcg5Rrk%3D' (2024-09-23)
  → 'github:NixOS/nixpkgs/1925c603f17fc89f4c8f6bf6f631a802ad85d784?narHash=sha256-J%2BPeFKSDV%2BpHL7ukkfpVzCOO7mBSrrpJ3svwBFABbhI%3D' (2024-09-26)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/a3d832f389606d7dc61a45b244c72ea472d1fcd4?narHash=sha256-yGYahXzCquyYEgf5GTtvtaN5hXbw20Ok2%2Bo8uVxoaFs%3D' (2024-09-26)
  → 'github:oxalica/rust-overlay/76f0a61e733259e1034dd6523e039d04932ffefc?narHash=sha256-kZCiYpQJBZ3kL9QymS88mCxpQwqo8KqvZeHk6LATuY8%3D' (2024-09-27)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>