flake.lock: Update

Flake lock file updates:

• Updated input 'nixpkgs':
    'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.886100%2Brev-08dacfca559e1d7da38f3cf05f1f45ee9bfd213c/019a329e-32b1-7e68-9599-4784bdd5f623/source.tar.gz' (2025-10-28)
  → 'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.964859%2Brev-b40629efe5d6ec48dd1efba650c797ddbd39ace0/019d03e9-2959-7276-adaa-d074e96422de/source.tar.gz' (2026-03-18)

flake.lock

@@ -2,12 +2,12 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1761672384,
-        "narHash": "sha256-o9KF3DJL7g7iYMZq9SWgfS1BFlNbsm6xplRjVlOCkXI=",
-        "rev": "08dacfca559e1d7da38f3cf05f1f45ee9bfd213c",
-        "revCount": 886100,
+        "lastModified": 1773821835,
+        "narHash": "sha256-TJ3lSQtW0E2JrznGVm8hOQGVpXjJyXY2guAxku2O9A4=",
+        "rev": "b40629efe5d6ec48dd1efba650c797ddbd39ace0",
+        "revCount": 964859,
         "type": "tarball",
-        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.886100%2Brev-08dacfca559e1d7da38f3cf05f1f45ee9bfd213c/019a329e-32b1-7e68-9599-4784bdd5f623/source.tar.gz"
+        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.964859%2Brev-b40629efe5d6ec48dd1efba650c797ddbd39ace0/019d03e9-2959-7276-adaa-d074e96422de/source.tar.gz"
       },
       "original": {
         "type": "tarball",