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/9a9fafd0c3f796b675acb2e16ae238d4fd2cbdb5?narHash=sha256-eZs7f4izo6t0AmOI1IAU6/ZbbXrxMPGdo%2Bkhe4hP3Rk%3D' (2024-05-25)
• 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/a55e8bf09cdfc25066b77823cc98976a51af8a8b?narHash=sha256-mVUbarr4PNjERDk%2BuaoitPq7eL7De0ythZehezAzug8%3D' (2024-05-24)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/d8fe5e6c92d0d190646fb9f1056741a229980089?narHash=sha256-iMUFArF0WCatKK6RzfUJknjem0H9m4KgorO/p3Dopkk%3D' (2024-03-29)
  → 'github:nixos/nixpkgs/bfb7a882678e518398ce9a31a881538679f6f092?narHash=sha256-4zSIhSRRIoEBwjbPm3YiGtbd8HDWzFxJjw5DYSDy1n8%3D' (2024-05-24)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/7cf3d11d06dcd12fb62ca2c039f3c5e25b53c5a7?narHash=sha256-I2/x/jFd7MAuIi3%2BkncIF0zJwhkFzxpi5XFdT2RLOF8%3D' (2024-03-30)
  → 'github:oxalica/rust-overlay/4d0f1e4d5d65c23cdbb77e4b0d91940be7309bd4?narHash=sha256-81u/zd7V%2BXRTq88zwRLxw5GnwZyEiAvGA2BvAXUe864%3D' (2024-05-25)