update nix dependencies with niv-update

* changes to nix-build output:

No version or selection state changes.
Closure size: 13 -> 13 (0 paths added, 0 paths removed, delta +0, disk usage +0B).

* changes to nix-shell output:

Version changes:
[U.]    libbacktrace-unstable  2022-12-16 -> 2023-11-30
Closure size: 1164 -> 1164 (67 paths added, 67 paths removed, delta +0, disk usage -952B).

nix/sources.json

@@ -5,10 +5,10 @@
         "homepage": "",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "ae5c332cbb5827f6b1f02572496b141021de335f",
-        "sha256": "1ldmdy9zhss014j30qhgwhv9bqjr03vfb30wx48psr8gj2ns3f3q",
+        "rev": "e92b6015881907e698782c77641aa49298330223",
+        "sha256": "0vq05559vmj5px94hr148wnq9qbn9whsfpwdbk8wn2myby4knwy7",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/ae5c332cbb5827f6b1f02572496b141021de335f.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/e92b6015881907e698782c77641aa49298330223.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "olderIdeaNixpkgs": {