flake.lock: Update (#1305)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/ab0f3607a6c7486ea22229b92ed2d355f1482ee0?narHash=sha256-zwE/e7CuPJUWKdvvTCB7iunV4E/%2BG0lKfv4kk/5Izdg%3D' (2025-09-10)
  → 'github:NixOS/nixpkgs/8eaee110344796db060382e15d3af0a9fc396e0e?narHash=sha256-iCGWf/LTy%2BaY0zFu8q12lK8KuZp7yvdhStehhyX1v8w%3D' (2025-09-19)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/3232f7f8bd07849fc6f4ae77fe695e0abb2eba2c?narHash=sha256-Jxl4OZRVsXs8JxEHUVQn3oPu6zcqFyGGKaFrlNgbzp0%3D' (2025-09-13)
  → 'github:oxalica/rust-overlay/f1ccb14649cf87e48051a6ac3a571b4a57d84ff3?narHash=sha256-2jaGMj32IckpZgBjn7kG4zyJl66T%2B2A1Fn2ppkHh91o%3D' (2025-09-20)

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