Restore BelleBuild target (for back-office assets) and use npm ci (#11364)

Co-authored-by: Ronald Barendse <ronald@barend.se>

tests/Umbraco.Tests.AcceptanceTest/package.json

@@ -1,4 +1,6 @@
 {
+  "name": "acceptancetest",
+  "private": true,
   "scripts": {
     "postinstall": "node postinstall.js",
     "config": "node config.js",
@@ -7,10 +9,10 @@
   },
   "devDependencies": {
     "cross-env": "^7.0.2",
-    "cypress": "^6.7.0",
+    "cypress": "^6.8.0",
     "del": "^6.0.0",
     "ncp": "^2.0.0",
-    "prompt": "^1.0.0",
+    "prompt": "^1.2.0",
     "umbraco-cypress-testhelpers": "^1.0.0-beta-58"
   },
   "dependencies": {