flake.lock: Update

Flake lock file updates:

• Updated input 'nightly':
    'github:nix-community/neovim-nightly-overlay/fdc7d407e29b17633d2568b5f46ead383ef85172?narHash=sha256-F5Obt4M07Jal6P0QMkbL9Qrsux7CmhbmEuO4d1NWOrk%3D' (2024-09-04)
  → 'github:nix-community/neovim-nightly-overlay/e8df4bbcb3a2d18a32d8a50bd72c3175227f7468?narHash=sha256-ybr3YTmjhVOuCWdacABUPxfUlVNqy0ya3s2sZ8zgyTw%3D' (2024-09-05)
• Updated input 'nightly/neovim-src':
    'github:neovim/neovim/7b7c95dac97d6ea4f10855cc198dce650a796c20?narHash=sha256-FEwqYuoLu5gZ6Kc8DWTKAWAR0iZ6dSvdIC9RARLKhWc%3D' (2024-09-03)
  → 'github:neovim/neovim/b6e350a6b4df40fcc99931c460668c36fadc9989?narHash=sha256-N%2BXyobzJsFXVivL/uu8lHSc9vxlM3j5SSOc4G9B0SyA%3D' (2024-09-04)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/b833ff01a0d694b910daca6e2ff4a3f26dee478c?narHash=sha256-tLGCFEFTB5TaOKkpfw3iYT9dnk4awTP/q4w%2BROpMfuw%3D' (2024-09-01)
  → 'github:nixos/nixpkgs/fcb54ddcc974cff59bdfb7c1ac9e080299763d2d?narHash=sha256-hd1eRyPtTkRnAPYpnEfzugQwAifVYMmOR3z%2BMTTSw%2Bg%3D' (2024-09-05)