flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/933bc78d45abaf764dbfe0fd117be981631f3e9a?narHash=sha256-79O83W9osY3wyvxZHqL0gw85tcACSX0TU5en3%2Bdky/0%3D' (2025-06-21)
  → 'github:nix-community/fenix/e91719882d0e4366202cc9058eb21df74c0bdb92?narHash=sha256-rSw0b/ahoZebcp%2BAZG7uoScB5Q59TYEE5Kx8k0pZp9E%3D' (2025-07-19)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/b0552d779f7137c76f109666ce0ad28395c0e582?narHash=sha256-EMFKnO%2BJ3dZOa9J%2BuiKZgHYgzALv9dqxY7NHV0DbO/U%3D' (2025-06-20)
  → 'github:rust-lang/rust-analyzer/330c4ed11c4e1eef0999a2cd629703a601da1436?narHash=sha256-YnG3d44oX%2Bg2ooUsNWT%2BIi24w6T%2Bb0dj86k0HkIFUj4%3D' (2025-07-18)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/076e8c6678d8c54204abcb4b1b14c366835a58bb?narHash=sha256-1ovgdmuDYVo5OUC5NzdF%2BV4zx2uT8RtsgZahxidBTyw%3D' (2025-06-20)
  → 'github:NixOS/nixpkgs/6b4955211758ba47fac850c040a27f23b9b4008f?narHash=sha256-dPALCtmik9Wr14MGqVXm%2BOQcv7vhPBXcWNIOThGnB/Q%3D' (2025-07-19)

Author: github-actions[bot]