Update index-state-hashes.nix

Author: IOHK

index-state-hashes.nix

@@ -2391,4 +2391,5 @@
   "2025-10-15T00:00:00Z" = "0d23a30f236256bf3e77f613410efb64c3ac52ce7e3640efb433008e41100858";
   "2025-10-16T00:00:00Z" = "92302222ae4713d84dac6867851d33afc41636ab7fe259102ed24e1344738c80";
   "2025-10-17T00:00:00Z" = "f0702b78763557537d4001ae5a132c62791b9d08d50f63d45695e2cbab475027";
+  "2025-10-18T00:00:00Z" = "31e71fa985e0a4f503173d386ed16bd756fe1c87b64eba825547a1789fb6d452";
 }