fix(updater): revert signing pubkey to 1DEAA803 to repair auto-update (#705)

Auto-update was broken on every platform: builds since aaf4ccc embed pubkey
6F4B5994, but shipped 1.3.8 stable users trust 1DEAA803 and CI now signs with
1DEAA803 again. A key the installed app doesn't trust => download succeeds,
install() signature verification fails => "downloads but never updates".

Revert the desktop updater pubkey to 1DEAA803 so it matches both the CI
signing key and android/updater.rs (which already hardcodes 1DEAA803). This
also repairs Android auto-update, which was signing-vs-verifying mismatched.
One line, no logic change.

Co-authored-by: sim <sim@local>

openless-all/app/src-tauri/tauri.conf.json

@@ -99,7 +99,7 @@
   },
   "plugins": {
     "updater": {
-      "pubkey": "dW50cnVzdGVkIGNvbW1lbnQ6IG1pbmlzaWduIHB1YmxpYyBrZXk6IDZGNEI1OTk0RjMzMzk0QTkKUldTcGxEUHpsRmxMYjRnMFdZNkFyaVozaHN2SUNwZ01mMDlFS0RMWnNQNisrWjF6czZQQk1RQysK",
+      "pubkey": "dW50cnVzdGVkIGNvbW1lbnQ6IG1pbmlzaWduIHB1YmxpYyBrZXk6IDFERUFBODAzNTY0QzMyM0YKUldRL01reFdBNmpxSGE1K0JadlpONXNWTzhJcGZCRGxjUVdIWExNNFJpeUNsSGZwazdlQThhemkK",
       "endpoints": [
         "https://github.com/appergb/openless/releases/latest/download/latest-{{target}}-{{arch}}.json",
         "https://fastgit.cc/https://github.com/appergb/openless/releases/latest/download/latest-{{target}}-{{arch}}-mirror.json"