ci: update flake.lock

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/049a6ecec1da711d3d84072732e4b14f98e0edd4?narHash=sha256-rX9GzfrzvjfqrjfyKnX%2BzmXTYNRZXqEUWUX2u%2BLBdi0%3D' (2024-06-25)
  → 'github:nix-community/fenix/2c06f54eb102f325f88472a9713f6d779726c2f7?narHash=sha256-TW68WegsA2KLjQMHTaP2//tLgXSaFiRdZKxKUc7vEtY%3D' (2024-06-30)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/7b11fdeb681c12002861b9804a388efde81c9647?narHash=sha256-%2BBgWRK3bWVIFwdn43DGRVscnu9P63Mndyhte/hgEwUA%3D' (2024-06-24)
  → 'github:rust-lang/rust-analyzer/9463d9eea4b87e651e7d8ed8425a9c92f23b1cdf?narHash=sha256-YzF4P6YVInAjcR5eJHWefkKEu5t70KYVZMvdLODv8CM%3D' (2024-06-28)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/a71e967ef3694799d0c418c98332f7ff4cc5f6af?narHash=sha256-CyyxvOwFf12I91PBWz43iGT1kjsf5oi6ax7CrvaMyAo%3D' (2024-06-22)
  → 'github:NixOS/nixpkgs/b2852eb9365c6de48ffb0dc2c9562591f652242a?narHash=sha256-C8e9S7RzshSdHB7L%2Bv9I51af1gDM5unhJ2xO1ywxNH8%3D' (2024-06-27)