automated: Update flake.lock

- The following Nix Flake inputs were updated:

```
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/3a228057f5b619feb3186e986dbe76278d707b6e?narHash=sha256-xvTo0Aw0%2Bveek7hvEVLzErmJyQkEcRk6PSR4zsRQFEc%3D' (2025-02-01)
  → 'github:NixOS/nixpkgs/5135c59491985879812717f4c9fea69604e7f26f?narHash=sha256-Vr3Qi346M%2B8CjedtbyUevIGDZW8LcA1fTG0ugPY/Hic%3D' (2025-02-26)
```

Auto-generated by [update.yml][1] with the help of
[create-pull-request][2].

[1]: https://forgejo.stefka.eu/jiriks74/nix.nvim/src/branch/main/.github/workflows/update.yml
[2]: https://forgejo.stefka.eu/jiriks74/create-pull-request

flake.lock

@@ -181,11 +181,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1738410390,
-        "narHash": "sha256-xvTo0Aw0+veek7hvEVLzErmJyQkEcRk6PSR4zsRQFEc=",
+        "lastModified": 1740560979,
+        "narHash": "sha256-Vr3Qi346M+8CjedtbyUevIGDZW8LcA1fTG0ugPY/Hic=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "3a228057f5b619feb3186e986dbe76278d707b6e",
+        "rev": "5135c59491985879812717f4c9fea69604e7f26f",
         "type": "github"
       },
       "original": {