flake.lock: Update

Flake lock file updates:

• Updated input 'nightly-overlay':
    'github:nix-community/neovim-nightly-overlay/16157dadce1649b112e32f7a0cb177afb74240cb?narHash=sha256-2RZ8apkzWxLuO9MKDE77CfJHJ2pkgyJFi5slD6A62s4%3D' (2024-12-18)
  → 'github:nix-community/neovim-nightly-overlay/1bac49debd490fc69306e117c6da95a523bd7c35?narHash=sha256-Q8E0fL3BLA1qxNIZZEbb3IAGYucqyUYe/rrmzjGrEkc%3D' (2024-12-19)
• Updated input 'nightly-overlay/neovim-src':
    'github:neovim/neovim/0dd933265ff2e64786fd30f949e767e10f401519?narHash=sha256-xAYMp%2BWC5lCgOG4bk3d4JYkPRqc/6bPiggphc0%2B%2Bdv8%3D' (2024-12-17)
  → 'github:neovim/neovim/02bc40c19401ea9f7529cbc81bd18bd01c39bb3c?narHash=sha256-lFSBvz6gLvOE%2B7HXt6H9MrMBHlznMluUb1JbAJQwdA4%3D' (2024-12-18)
• Updated input 'nightly-overlay/treefmt-nix':
    'github:numtide/treefmt-nix/0ce9d149d99bc383d1f2d85f31f6ebd146e46085?narHash=sha256-s4DalCDepD22jtKL5Nw6f4LP5UwoMcPzPZgHWjAfqbQ%3D' (2024-12-09)
  → 'github:numtide/treefmt-nix/76159fc74eeac0599c3618e3601ac2b980a29263?narHash=sha256-/QceWozrNg915Db9x/Ie5k67n9wKgGdTFng%2BZ1Qw0kE%3D' (2024-12-18)