Remove marketplace preview flag (#1369)

Author: testforstephen

package.json

@@ -4,7 +4,7 @@
   "description": "A lightweight Java debugger for Visual Studio Code",
   "version": "0.52.0",
   "publisher": "vscjava",
-  "preview": true,
+  "preview": false,
   "aiKey": "67d4461e-ccba-418e-8082-1bd0acfe8516",
   "icon": "logo.png",
   "workspaceTrust": {