flake.lock: Update

Flake lock file updates:

• Updated input 'flake-utils':
    'github:numtide/flake-utils/4022d587cbbfd70fe950c1e2083a02621806a725' (2023-12-04)
  → 'github:numtide/flake-utils/b1d9ab70662946ef0850d488da1c9019f3a9752a' (2024-03-11)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/91050ea1e57e50388fa87a3302ba12d188ef723a' (2023-12-01)
  → 'github:NixOS/nixpkgs/44d0940ea560dee511026a53f0e2e2cde489b4d4' (2024-03-23)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/1fdfc1689218998460983986501bd65ba5bbee0f' (2023-12-06)
  → 'github:oxalica/rust-overlay/6529a7975b893c17318cbdd351c771cb8d2c1dcb' (2024-03-23)
• Updated input 'rust-overlay/flake-utils':
    'github:numtide/flake-utils/cfacdce06f30d2b68473a46042957675eebb3401' (2023-04-11)
  → 'github:numtide/flake-utils/1ef2e671c3b0c19053962c07dbda38332dcebf26' (2024-01-15)
• Updated input 'rust-overlay/nixpkgs':
    'github:NixOS/nixpkgs/96ba1c52e54e74c3197f4d43026b3f3d92e83ff9' (2023-04-13)
  → 'github:NixOS/nixpkgs/90f456026d284c22b3e3497be980b2e47d0b28ac' (2024-01-29)