chore(nix): update nixpkgs-unstable to d4221905 (#44)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

flake.lock

@@ -735,11 +735,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1784555310,
-        "narHash": "sha256-/FCliTPgiuV1owejZFNx3Ch9irdvkOfOFl+HHZ+DrtM=",
+        "lastModified": 1784835677,
+        "narHash": "sha256-99n/+kX5HRtEouTsNNyz5pMfIpNMp4Um/6nCEDQ9YDs=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "421eebfd0ec7bccd4abe826ce62d7e6e83129493",
+        "rev": "d4221905ef70b7f4a40701ce98e3e25c3d95d082",
         "type": "github"
       },
       "original": {
@@ -873,11 +873,11 @@
     },
     "nixpkgs_8": {
       "locked": {
-        "lastModified": 1784707089,
-        "narHash": "sha256-2V/6imsUgB7mPZlHY54oeVBRDoZbPKnvzwkAHUSSufk=",
+        "lastModified": 1784835692,
+        "narHash": "sha256-yPpild1rF2EqcvlzprUlTbtZxJ44KsjEuDRtctIybOQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "b3fe9581c9061c749abef42b6d4ee7b7c05c33fa",
+        "rev": "c76cb9d6c25d19547d892782bd84b22fc7b04d5f",
         "type": "github"
       },
       "original": {