Update nixpkgs

flake.lock

@@ -2,11 +2,12 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1623154001,
-        "narHash": "sha256-KxsIXg5ez5SveGayOKcW+MnofqVuLnwZHE5mZgtRAJo=",
-        "path": "/nix/store/r35z76cadipjzjrjik06gp1kfbqlhdck-source",
-        "rev": "3bc8e5cd23b84b2e149e7aaad57117da16a19e6f",
-        "type": "path"
+        "lastModified": 1627857416,
+        "narHash": "sha256-AV0MsFVzbWI2MZbJ2j0kc8ooFLGSCZHuM9ipaWR9ds4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "aaf9676fbb7fb4570216ca1e189a3dc769d62c45",
+        "type": "github"
       },
       "original": {
         "id": "nixpkgs",