automated: Update flake.lock

- The following Nix Flake inputs were updated:

```
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/6df24922a1400241dae323af55f30e4318a6ca65?narHash=sha256-dklw3AXr3OGO4/XT1Tu3Xz9n/we8GctZZ75ZWVqAVhk%3D' (2025-01-02)
  → '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

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1735834308,
-        "narHash": "sha256-dklw3AXr3OGO4/XT1Tu3Xz9n/we8GctZZ75ZWVqAVhk=",
+        "lastModified": 1740560979,
+        "narHash": "sha256-Vr3Qi346M+8CjedtbyUevIGDZW8LcA1fTG0ugPY/Hic=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "6df24922a1400241dae323af55f30e4318a6ca65",
+        "rev": "5135c59491985879812717f4c9fea69604e7f26f",
         "type": "github"
       },
       "original": {