remove bad plugins

package.json

@@ -38,9 +38,6 @@
   "dependencies": {
     "@koishijs/cli": "^4.7.5",
     "@koishijs/loader": "^1.0.1",
-    "@koishijs/plugin-database-mysql": "^4.4.3",
-    "@koishijs/plugin-help": "^1.0.1",
-    "@koishijs/plugin-suggest": "^1.1.0",
     "koishi": "^4.7.5",
     "load-json-file": "^6.2.0",
     "ws": "^8.2.3",