flake.lock: Update

Flake lock file updates:

• Updated input 'merlin5_2':
    'github:ocaml/merlin/9dcffb9e998703f5f5d6e7c575c30cd822cea210?narHash=sha256-ZJFtPreWenLlXDokh3dOR%2Bb3LRuZJgs9%2B6r%2BtEx9/Vo%3D' (2025-01-10)
  → 'github:ocaml/merlin/86b4b261b950e409791a42815e4ede601c6be92d?narHash=sha256-uDCedJ29otDXKfz%2BUngiQmJqmKG2iG4JBHST1dbU79A%3D' (2025-01-13)
• Updated input 'nixpkgs':
    'github:nix-ocaml/nix-overlays/be7cfa6043ed31b17e4b86769c05825c62e55829?narHash=sha256-Ct6RqUtqIfazkg1X4o2FXWuYpw0A%2BOJsd3cFGtmXaqk%3D' (2025-01-09)
  → 'github:nix-ocaml/nix-overlays/70d5fcca4b0fb7b9b071de7f13a975b517ebb036?narHash=sha256-xRPiXsyqAkH9lze8WerGyr1FSBRxWvFaCsw7zKaTWPc%3D' (2025-01-25)
• Updated input 'nixpkgs/nixpkgs':
    'github:NixOS/nixpkgs/8e97141d59b87e2bf254cd0920be29955d45a698?narHash=sha256-h0hPzFp7iVhCqzBx%2BkJGdO/KmG8AkYRJ0jKxQ6%2Bdiug%3D' (2025-01-09)
  → 'github:NixOS/nixpkgs/ed45d51fb4c860e70760a042dd9ff99bd016497e?narHash=sha256-0kGPO515JdDt6gPcR25QTGyNJnT1UFtH1tdkR2QdLAY%3D' (2025-01-25)

Author: github-actions[bot]