flake.lock: Update

Flake lock file updates:

• Updated input 'sandkasten':
    'github:Defelo/sandkasten/1e97b989069e87700c7283c036b45231d1eca647' (2024-09-10)
  → 'github:Defelo/sandkasten/d1456632f1b2ed3676bbe8ed7c5e22388784fe25' (2024-09-12)
• Updated input 'sandkasten/fenix':
    'github:nix-community/fenix/4b8d964df93d1f918ee6c4f003b3548c432cc866' (2024-09-07)
  → 'github:nix-community/fenix/96a04a213838c5001619ad57400c5a176fa040b1' (2024-09-12)
• Updated input 'sandkasten/fenix/nixpkgs':
    'github:nixos/nixpkgs/ad416d066ca1222956472ab7d0555a6946746a80' (2024-09-04)
  → 'github:nixos/nixpkgs/574d1eac1c200690e27b8eb4e24887f8df7ac27c' (2024-09-06)
• Updated input 'sandkasten/fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/08c7bbc2dbe4dcc8968484f1a0e1e6fe7a1d4f6d' (2024-09-06)
  → 'github:rust-lang/rust-analyzer/bcc708992104c2059f310fbc3ac00bfc377f9ea8' (2024-09-10)
• Updated input 'sandkasten/nixpkgs':
    'github:NixOS/nixpkgs/a69b3373fbc9deedd1d91ee269c6d274db2c3d28' (2024-09-08)
  → 'github:NixOS/nixpkgs/ebd7499d1399a88484888028cc2dd2843f2b854c' (2024-09-12)
• Updated input 'sandkasten/nixpkgs-master':
    'github:NixOS/nixpkgs/ad60caf890f7010998174b5126580360b0567151' (2024-09-08)
  → 'github:NixOS/nixpkgs/7f114dae532fbba5ae881311097f343ffee740bd' (2024-09-12)