flake.lock: Update (#493)

Flake lock file updates:

• Updated input 'neovim-nightly':
    'github:nix-community/neovim-nightly-overlay/8171f4020066019bdaff49b96de957da142df41a?narHash=sha256-1EdXM4OQYSnFL/0YHXjtt/yei2jPHLOECISY3DITDMQ%3D' (2025-02-14)
  → 'github:nix-community/neovim-nightly-overlay/431a128acf3048670ff80048dde2a172045a062f?narHash=sha256-ipXtyL3JbBsJA%2BAxr5FGVcP28vfrIyOisVCSyjud4vA%3D' (2025-02-15)
• Updated input 'neovim-nightly/neovim-src':
    'github:neovim/neovim/6b387bde6963f73a1ba38d48070945ee6004ea6f?narHash=sha256-lTOH7YQ7JceohH25Nw7rIHS/Y1vQbH2yOyPCzURvi%2BE%3D' (2025-02-13)
  → 'github:neovim/neovim/10a3a854736895783aac9fd5dd86156f7ae25df1?narHash=sha256-4gqndlNmaA0h2gm/y7rW/Jg3CSpyAgGm3O3ox8dWLxE%3D' (2025-02-14)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>