Ensure electron-builder and electron-rebuild use N-API v3 prebuilds

package.json

@@ -70,7 +70,7 @@
     "Roman Malieiev <aromaleev@gmail.com>"
   ],
   "scripts": {
-    "install": "(node install/libvips && node install/dll-copy && prebuild-install --runtime=napi) || (node-gyp rebuild && node install/dll-copy)",
+    "install": "(node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)",
     "clean": "rm -rf node_modules/ build/ vendor/ .nyc_output/ coverage/ test/fixtures/output.*",
     "test": "semistandard && cpplint && npm run test-unit && npm run test-licensing && prebuild-ci",
     "test-unit": "nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
@@ -137,7 +137,9 @@
   },
   "license": "Apache-2.0",
   "config": {
-    "libvips": "8.10.0-beta2"
+    "libvips": "8.10.0-beta2",
+    "runtime": "napi",
+    "target": 3
   },
   "engines": {
     "node": ">=10.16.0"