fix(nix): refresh upstream Nix pins for 26.707.91948 (ilysenko#1020)

Refreshed Codex.dmg SRI hash to sha256-Wiq5aJ9Lo4/LE1VlJG1covEk1Tkzagoyr823IEDSFGY= and synced codexVersion / electronVersion / native-module pins to the current upstream DMG.

Verified all ChatGPT Desktop Nix package outputs against the refreshed DMG.

[skip ci]

Source-Main-SHA: 3a3caa7

Upstream-DMG-SHA256: 5a2ab9689f4ba38fcb135565246d5ca2f124d539336a0a32afcdb72040d21466

Co-authored-by: codex-dmg-hash-bot <actions@github.com>

Author: github-actions[bot]

flake.nix

@@ -94,10 +94,10 @@
 
         codexDmg = pkgs.fetchurl {
           url = "https://persistent.oaistatic.com/codex-app-prod/ChatGPT.dmg";
-          hash = "sha256-QONIFOdOMJQ8IJ69TalM1N41gaUsW/++K88uSI1jYcY=";
+          hash = "sha256-Wiq5aJ9Lo4/LE1VlJG1covEk1Tkzagoyr823IEDSFGY=";
         };
 
-        codexVersion = "26.707.72221";
+        codexVersion = "26.707.91948";
         electronVersion = "42.1.0";
         electronPlatform =
           {