Update server for Node rollback to fix v18 issues

Author: pimterry

package.json

@@ -21,7 +21,7 @@
   "author": "Tim Perry",
   "license": "AGPL-3.0-or-later",
   "config": {
-    "httptoolkit-server-version": "1.12.8"
+    "httptoolkit-server-version": "1.12.9"
   },
   "build": {
     "appId": "tech.httptoolkit.desktop",