automated: Update flake.lock

- The following Nix Flake inputs were updated:

```
• Updated input 'home-manager':
    'github:nix-community/home-manager/fb061f555f821fe4fb49f8f6f2a0cc3d5728bd52?narHash=sha256-IDsM/9/tHQBlhG3tXI2fTM84AUN1uRa7JDPT1LMlGes%3D' (2025-05-12)
  → 'github:nix-community/home-manager/6911d3e7f475f7b3558b4f5a6aba90fa86099baa?narHash=sha256-QdenO8f0PTg%2BtC6HuSvngKcbRZA5oZKmjUT%2BMXKOLQg%3D' (2025-08-21)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/d89fc19e405cb2d55ce7cc114356846a0ee5e956?narHash=sha256-3e%2BAVBczosP5dCLQmMoMEogM57gmZ2qrVSrmq9aResQ%3D' (2025-05-10)
  → 'github:NixOS/nixpkgs/20075955deac2583bb12f07151c2df830ef346b4?narHash=sha256-HMwfAJBdrr8wXAkbGhtcby1zGFvs%2BStOp19xNsbqdOg%3D' (2025-08-19)
```

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

@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1747021744,
+        "lastModified": 1755810213,
-        "narHash": "sha256-IDsM/9/tHQBlhG3tXI2fTM84AUN1uRa7JDPT1LMlGes=",
+        "narHash": "sha256-QdenO8f0PTg+tC6HuSvngKcbRZA5oZKmjUT+MXKOLQg=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "fb061f555f821fe4fb49f8f6f2a0cc3d5728bd52",
+        "rev": "6911d3e7f475f7b3558b4f5a6aba90fa86099baa",
         "type": "github"
       },
       "original": {
@@ -22,11 +22,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1746904237,
+        "lastModified": 1755615617,
-        "narHash": "sha256-3e+AVBczosP5dCLQmMoMEogM57gmZ2qrVSrmq9aResQ=",
+        "narHash": "sha256-HMwfAJBdrr8wXAkbGhtcby1zGFvs+StOp19xNsbqdOg=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d89fc19e405cb2d55ce7cc114356846a0ee5e956",
+        "rev": "20075955deac2583bb12f07151c2df830ef346b4",
         "type": "github"
       },
       "original": {