flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/94a5b9a4f8df7b2fa328044b8908b892a2733f60' (2023-09-09)
  → 'github:nix-community/fenix/95d6c30ecac01307772ec4273c649dab40211a9e' (2023-09-16)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/c405509f2e61cadaa8b18f340582e5c362356f2d' (2023-09-08)
  → 'github:rust-lang/rust-analyzer/12e28c35758051dd6bc9cdf419a50dff80fab64d' (2023-09-14)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/b200e0df08f80c32974a6108ce431d8a8a5e6547' (2023-09-07)
  → 'github:NixOS/nixpkgs/46688f8eb5cd6f1298d873d4d2b9cf245e09e88e' (2023-09-15)
• Updated input 'utils':
    'github:numtide/flake-utils/f9e7cf818399d17d347f847525c5a5a8032e4e44' (2023-08-23)
  → 'github:numtide/flake-utils/ff7b65b44d01cf9ba6a71320833626af21126384' (2023-09-12)