flake: update inputs (#394)

Flake lock file updates:

• Updated input 'nixpkgs-stable':
    'github:NixOS/nixpkgs/6e6b3dd395c3b1eb9be9f2d096383a8d05add030?narHash=sha256-/uJcVXuBt%2BVFCPQIX%2B4YnYrHaubJSx4HoNsJVNRgANM%3D' (2024-10-04)
  → 'github:NixOS/nixpkgs/ecbc1ca8ffd6aea8372ad16be9ebbb39889e55b6?narHash=sha256-PbDWAIjKJdlVg%2BqQRhzdSor04bAPApDqIv2DofTyynk%3D' (2024-10-06)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/d1d2532ab267cfe6e40dff73fbaf34436c406d26?narHash=sha256-X62hA5ivYLY5G5%2BmXI6l9eUDkgi6Wu/7QUrwXhJ09oo%3D' (2024-10-05)
  → 'github:oxalica/rust-overlay/cd46aa3906c14790ef5cbe278d9e54f2c38f95c0?narHash=sha256-sQXHXsjIcGEoIHkB%2BRO6BZdrPfB%2B43V1TEpyoWRI3ww%3D' (2024-10-06)

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