flake.lock: Update (#4079)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/495b19d5b3e62b4ec7e846bdfb6ef3d9c3b83492' (2022-08-19)
  → 'github:NixOS/nixpkgs/f3d0897be466aa09a37f6bf59e62c360c3f9a6cc' (2022-08-25)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/33aaf88ac9f5f7115eca96e784e96e519c670b18' (2022-08-20)
  → 'github:oxalica/rust-overlay/790c16639c7d8da8b36d0aa6a7c1f589af8c5f68' (2022-08-27)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]