flake.lock: Update (#1)

Flake lock file updates:

• Updated input 'nightly':
    'github:nix-community/neovim-nightly-overlay/48f92fd7f42dd4b01e55dbe0baaf21c4a270a076?narHash=sha256-sfE3ACZSo7I2ahByRsU66X%2BxmzAz4qSxl4IipSD7ObM%3D' (2024-06-29)
  → 'github:nix-community/neovim-nightly-overlay/643ec69ac0cfcc1cd26523c3816fb111e5bb3a41?narHash=sha256-bsZDPD08s8FKCGyy1OMMuM%2BcOjO1M8vPREkhgyqkRQM%3D' (2024-06-30)
• Updated input 'nightly/neovim-src':
    'github:neovim/neovim/435d0182d293e70b14a5655c976c3c6daa6ea765?narHash=sha256-97hP/z7sH4GUBBVi2Z7QiJsgIOO6a%2BAFYf4MvTU2p0Y%3D' (2024-06-29)
  → 'github:neovim/neovim/e7020306a19a5211c834966ec067fff3b981bdb9?narHash=sha256-d89hDFBBtuQ7rwS/Q3lKYyfE0ekVCwubMN9q1qCZ3m0%3D' (2024-06-29)

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