core: use common plugin-api interface

packages/login-with-google/package.json

@@ -6,13 +6,7 @@
     "author": "undefined <i@undefined.moe>",
     "license": "AGPL-3.0-or-later",
     "preferUnplugged": true,
-    "devDependencies": {
-        "@types/superagent": "^4.1.15"
-    },
     "peerDependencies": {
         "hydrooj": "*"
-    },
-    "dependencies": {
-        "superagent": "^8.0.0"
     }
 }