flake.lock: Update

Flake lock file updates:

• Updated input 'dream2nix':
    'github:nix-community/dream2nix/262198033e23e9ee832f0cc8133d38f07598f555' (2023-12-13)
  → 'github:nix-community/dream2nix/400032c6303f82b07a09c9784ab5569a51544987' (2024-04-09)
• Updated input 'flake-utils':
    'github:numtide/flake-utils/ff7b65b44d01cf9ba6a71320833626af21126384' (2023-09-12)
  → 'github:numtide/flake-utils/b1d9ab70662946ef0850d488da1c9019f3a9752a' (2024-03-11)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/886c9aee6ca9324e127f9c2c4e6f68c2641c8256' (2023-12-18)
  → 'github:NixOS/nixpkgs/a76c4553d7e741e17f289224eda135423de0491d' (2024-04-09)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/cbdf3e5bb205ff2ca165fe661fbd6d885cbd0106' (2024-02-26)
  → 'github:oxalica/rust-overlay/e7354bb9e5f68b2074e272fd5f5ac3f4848860ba' (2024-04-09)
• Updated input 'sops-nix':
    'github:Mic92/sops-nix/e19071f9958c8da4f4347d3d78790d97e98ba22f' (2023-12-02)
  → 'github:Mic92/sops-nix/538c114cfdf1f0458f507087b1dcf018ce1c0c4c' (2024-04-08)
• Updated input 'sops-nix/nixpkgs-stable':
    'github:NixOS/nixpkgs/dfb95385d21475da10b63da74ae96d89ab352431' (2023-11-25)
  → 'github:NixOS/nixpkgs/e38d7cb66ea4f7a0eb6681920615dfcc30fc2920' (2024-04-06)
• Updated input 'treefmt-nix':
    'github:numtide/treefmt-nix/e82f32aa7f06bbbd56d7b12186d555223dc399d1' (2023-11-12)
  → 'github:numtide/treefmt-nix/49dc4a92b02b8e68798abd99184f228243b6e3ac' (2024-04-01)