flake: update inputs

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/9357f4f23713673f310988025d9dc261c20e70c6?narHash=sha256-bvGoiQBvponpZh8ClUcmJ6QnsNKw0EMrCQJARK3bI1c%3D' (2024-09-21)
  → 'github:NixOS/nixpkgs/30439d93eb8b19861ccbe3e581abf97bdc91b093?narHash=sha256-o8VBeCWHBxGd4kVMceIayf5GApqTavJbTa44Xcg5Rrk%3D' (2024-09-23)
• Updated input 'nixpkgs-stable':
    'github:NixOS/nixpkgs/babc25a577c3310cce57c72d5bed70f4c3c3843a?narHash=sha256-nPyrcFm6FSk7CxzVW4x2hu62aLDghNcv9dX6DF3dXw8%3D' (2024-09-23)
  → 'github:NixOS/nixpkgs/759537f06e6999e141588ff1c9be7f3a5c060106?narHash=sha256-KQPI8CTTnB9CrJ7LrmLC4VWbKZfljEPBXOFGZFRpxao%3D' (2024-09-25)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/b5f76c3b09a8194889f5328a480fbea1a9115518?narHash=sha256-XLloPtQHKk/Tdt8t8zIb%2BJhmunlH3YB9Jz8RTlQ3N/4%3D' (2024-09-25)
  → 'github:oxalica/rust-overlay/a3d832f389606d7dc61a45b244c72ea472d1fcd4?narHash=sha256-yGYahXzCquyYEgf5GTtvtaN5hXbw20Ok2%2Bo8uVxoaFs%3D' (2024-09-26)