flake.lock: Update

Flake lock file updates:

```
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/26d499fc9f1d567283d5d56fcf367edd815dba1d' (2025-04-12)
  → 'github:nixos/nixpkgs/bf3287dac860542719fe7554e21e686108716879' (2025-05-02)
• Updated input 'nixpkgs-unstable':
    'github:nixos/nixpkgs/b024ced1aac25639f8ca8fdfc2f8c4fbd66c48ef' (2025-04-17)
  → 'github:nixos/nixpkgs/7a2622e2c0dbad5c4493cb268aba12896e28b008' (2025-05-03)
```

flake.lock

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1745921652,
-        "narHash": "sha256-hEAvEN+y/OQ7wA7+u3bFJwXSe8yoSf2QaOMH3hyTJTQ=",
+        "lastModified": 1746183838,
+        "narHash": "sha256-kwaaguGkAqTZ1oK0yXeQ3ayYjs8u/W7eEfrFpFfIDFA=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "b000159bba69b0106a42f65e52dbf27f77aca9d3",
+        "rev": "bf3287dac860542719fe7554e21e686108716879",
         "type": "github"
       },
       "original": {
@@ -36,11 +36,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1745930157,
-        "narHash": "sha256-y3h3NLnzRSiUkYpnfvnS669zWZLoqqI6NprtLQ+5dck=",
+        "lastModified": 1746232882,
+        "narHash": "sha256-MHmBH2rS8KkRRdoU/feC/dKbdlMkcNkB5mwkuipVHeQ=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "46e634be05ce9dc6d4db8e664515ba10b78151ae",
+        "rev": "7a2622e2c0dbad5c4493cb268aba12896e28b008",
         "type": "github"
       },
       "original": {