flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/aaeaf4574767a0f5ed1787e990139aefcf4db103?narHash=sha256-iGb6ptUaNBOCftKnNJiWT5z1ftngfNtwqJkD8Z9Vwfw%3D' (2024-03-30)
  → 'github:nix-community/fenix/3717a9f4981495d5487642554343acfacf4e64fa?narHash=sha256-b7j/GL7Pvmx9zpGnqjDzrTtLZktipsZSHJyMrLRQRKU%3D' (2024-07-27)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/f5a9250147f6569d8d89334dc9cca79c0322729f?narHash=sha256-dyezzeSbWMpflma%2BE9USmvSxuLgGcNGcGw3cOnX36ko%3D' (2024-03-29)
  → 'github:rust-lang/rust-analyzer/aae54dde8c384acc310455504c9d8909646e0778?narHash=sha256-RenI%2B4lnrMH0DFLU4HlgCZ9X5yadeishI5Liy2XqNOQ%3D' (2024-07-26)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/d8fe5e6c92d0d190646fb9f1056741a229980089?narHash=sha256-iMUFArF0WCatKK6RzfUJknjem0H9m4KgorO/p3Dopkk%3D' (2024-03-29)
  → 'github:nixos/nixpkgs/b73c2221a46c13557b1b3be9c2070cc42cf01eb3?narHash=sha256-QOS0ykELUmPbrrUGmegAUlpmUFznDQeR4q7rFhl8eQg%3D' (2024-07-27)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/db12d0c6ef002f16998723b5dd619fa7b8997086?narHash=sha256-6eaaoJUkr4g9J/rMC4jhj3Gv8Sa62rvlpjFe3xZaSjM%3D' (2024-07-02)
  → 'github:oxalica/rust-overlay/56baac5e6b2743d4730e664ea64f6d8a2aad0fbb?narHash=sha256-G7/gHz8ORRvHd1/RIURrdcswKRPe9K0FsIYR4v5jSWo%3D' (2024-07-27)