flake.lock: Update

Flake lock file updates:

• Updated input 'secrets':
    'git+ssh://git@git.caspervk.net/caspervk/nixos-secrets.git?ref=refs/heads/master&rev=725ccdd9169ae40d56f1b07f53918e4e27898c08' (2025-01-22)
  → 'git+ssh://git@git.caspervk.net/caspervk/nixos-secrets.git?ref=refs/heads/master&rev=21dba31dcb0e91afc3e64ee250366f60c34785f5' (2025-01-29)

flake.lock

@@ -214,11 +214,11 @@
     },
     "secrets": {
       "locked": {
-        "lastModified": 1737510423,
-        "narHash": "sha256-FjyBCMyzYcQUW9J7VsMB9fTVrQpYHLlLNjcZpxdMB2I=",
+        "lastModified": 1738115505,
+        "narHash": "sha256-xUrsDpieatAvXaXN35yFQWEQK7QJKq8e92aVBbnUcNQ=",
         "ref": "refs/heads/master",
-        "rev": "725ccdd9169ae40d56f1b07f53918e4e27898c08",
-        "revCount": 54,
+        "rev": "21dba31dcb0e91afc3e64ee250366f60c34785f5",
+        "revCount": 55,
         "type": "git",
         "url": "ssh://git@git.caspervk.net/caspervk/nixos-secrets.git"
       },