flake.lock: Update

Flake lock file updates:

• Updated input 'cabal':
    'github:stable-haskell/cabal/c0d52b2' (2025-03-30)
  → 'github:stable-haskell/cabal/0a74ea1' (2025-07-28)
• Updated input 'cabal-experimental':
    'github:stable-haskell/cabal/7e50837' (2025-04-07)
  → 'github:stable-haskell/cabal/7ea381f' (2025-05-22)
• Updated input 'haskellNix':
    'github:input-output-hk/haskell.nix/835d1d8' (2025-04-04)
  → 'github:input-output-hk/haskell.nix/a62c9d8' (2025-12-06)
• Removed input 'haskellNix/ghc-8.6.5-iohk'
• Updated input 'haskellNix/hackage':
    'github:input-output-hk/hackage.nix/9f3c25c' (2025-04-04)
  → 'github:input-output-hk/hackage.nix/a7cf7e3' (2025-12-06)
• Updated input 'haskellNix/hackage-for-stackage':
    'github:input-output-hk/hackage.nix/fdd3d2b' (2025-04-04)
  → 'github:input-output-hk/hackage.nix/dc84ef2' (2025-12-06)
• Added input 'haskellNix/hackage-internal':
    'github:input-output-hk/hackage.nix/f7867ba' (2025-06-19)
• Added input 'haskellNix/hls-2.11':
    'github:haskell/haskell-language-server/46ef452' (2025-05-15)
• Updated input 'haskellNix/iserv-proxy':
    'github:stable-haskell/iserv-proxy/e9dc86e' (2025-03-16)
  → 'github:stable-haskell/iserv-proxy/1506051' (2025-08-15)
• Updated input 'haskellNix/nixpkgs-2411':
    'github:NixOS/nixpkgs/94792ab' (2025-02-10)
  → 'github:NixOS/nixpkgs/5ab036a' (2025-06-30)
• Added input 'haskellNix/nixpkgs-2505':
    'github:NixOS/nixpkgs/6c8f0cc' (2025-12-01)
• Added input 'haskellNix/nixpkgs-2511':
    'github:NixOS/nixpkgs/b0924ea' (2025-12-01)
• Updated input 'haskellNix/nixpkgs-unstable':
    'github:NixOS/nixpkgs/041c867' (2025-01-17)
  → 'github:NixOS/nixpkgs/c1cb7d0' (2025-12-01)
• Updated input 'haskellNix/stackage':
    'github:input-output-hk/stackage.nix/b7d2fd6' (2025-04-04)
  → 'github:input-output-hk/stackage.nix/4cbb79a' (2025-12-06)
• Updated input 'iohk-nix':
    'github:input-output-hk/iohk-nix/3acad18' (2025-04-03)
  → 'github:input-output-hk/iohk-nix/a704b93' (2025-11-12)
• Updated input 'iohk-nix/nixpkgs':
    'github:nixos/nixpkgs/55af203' (2023-05-15)
  → 'github:nixos/nixpkgs/a47938d' (2025-06-28)

Author: github-actions[bot]