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/6643d56d9a78afa157b577862c220298c09b891d?narHash=sha256-vmbu97JXqr9/sTWR5XRh646jkp8a0J9m0o6JIQTdjE4%3D' (2025-06-28)
• 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/317542c1e4a3ec3467d21d1c25f6a43b80d83e7d?narHash=sha256-hMNZXMtlhfjQdu1F4Fa/UFiMoXdZag4cider2R9a648%3D' (2025-06-25)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/076e8c6678d8c54204abcb4b1b14c366835a58bb?narHash=sha256-1ovgdmuDYVo5OUC5NzdF%2BV4zx2uT8RtsgZahxidBTyw%3D' (2025-06-20)
  → 'github:NixOS/nixpkgs/80d50fc87924c2a0d346372d242c27973cf8cdbf?narHash=sha256-3u6rEbIX9CN/5A5/mc3u0wIO1geZ0EhjvPBXmRDHqWM%3D' (2025-06-27)

Author: github-actions[bot]