chore(flake): update flake.lock (#357)

Flake lock file updates:

• Updated input 'emacs-overlay':
    'github:nix-community/emacs-overlay/6944d9b030689cf37cdf01e14fa828fff195d8f7' (2024-06-22)
  → 'github:nix-community/emacs-overlay/012409732a53433d75db7bb2e06dd0bdaf8ca7ea' (2024-06-29)
• Updated input 'emacs-overlay/nixpkgs-stable':
    'github:NixOS/nixpkgs/03d771e513ce90147b65fe922d87d3a0356fc125' (2024-06-19)
  → 'github:NixOS/nixpkgs/90bd1b26e23760742fdcb6152369919098f05417' (2024-06-24)
• Updated input 'melpa':
    'github:melpa/melpa/3cc337cbfdd1f09e6a18bbbe8f8cf470601a2db4' (2024-06-24)
  → 'github:melpa/melpa/1839deb57d34adc76db0b1a1a877b3cb542a6810' (2024-06-26)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/165dfa10e2983708c5eae03a1f02674b5d03208a' (2024-06-22)
  → 'github:NixOS/nixpkgs/5e87fb56fd499ee4090e6ed939561a9470ac5f53' (2024-06-29)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>