chore(npins): Update nixos-unstable

npins/sources.json

@@ -304,8 +304,8 @@
     "nixos-unstable": {
       "type": "Channel",
       "name": "nixos-unstable",
-      "url": "https://releases.nixos.org/nixos/unstable/nixos-25.05beta750470.a3eaf5e8eca7/nixexprs.tar.xz",
+      "url": "https://releases.nixos.org/nixos/unstable/nixos-25.05beta761040.303bd8071377/nixexprs.tar.xz",
-      "hash": "10zdp7pgjqp2fwqshhdiraw8wfm437czzv0fqxicgn9d6akpgkqh"
+      "hash": "15xz52bchv05cd4yxi4qhym9l7z0qr7hnw34pl098rjikp6yqbvw"
     },
     "proxmox-nixos": {
       "type": "Git",