use schemagen as external

package.json

 {
   "name": "koishi-plugin-pics",
   "description": "Koishi 的随机图片插件",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "scripts": {
@@ -26,7 +26,8 @@
   },
   "homepage": "https://code.mycard.moe/3rdeye/koishi-plugin-pics",
   "dependencies": {
-    "source-map-support": "^0.5.20"
+    "source-map-support": "^0.5.20",
+    "koishi-utils-schemagen": "^1.1.7"
   },
   "peerDependencies": {
     "koishi": "^4.0.0-alpha.11"
@@ -40,7 +41,6 @@
     "eslint-config-prettier": "^8.3.0",
     "eslint-plugin-prettier": "^3.4.1",
     "koishi": "^4.0.0-alpha.11",
-    "koishi-utils-schemagen": "^1.1.7",
     "lodash": "^4.17.21",
     "prettier": "^2.4.1",
     "raw-loader": "^4.0.2",

webpack.config.js

-const path = require("path");
+const path = require('path');
 
 module.exports = {
-  entry: "./src/index.ts",
-  mode: "production",
-  target: "node",
-  devtool: "source-map",
+  entry: './src/index.ts',
+  mode: 'production',
+  target: 'node',
+  devtool: 'source-map',
   module: {
     rules: [
       {
         test: /\.tsx?$/,
-        use: "ts-loader",
+        use: 'ts-loader',
         exclude: /node_modules/,
       },
-      { test: /\.mustache$/, use: "raw-loader" },
+      { test: /\.mustache$/, use: 'raw-loader' },
     ],
   },
   resolve: {
-    extensions: [".tsx", ".ts", ".js"],
+    extensions: ['.tsx', '.ts', '.js'],
   },
   output: {
-    filename: "index.js",
+    filename: 'index.js',
     library: {
-      type: "commonjs",
+      type: 'commonjs',
     },
-    path: path.resolve(__dirname, "dist"),
+    path: path.resolve(__dirname, 'dist'),
   },
   externals: {
-    'koishi': 'koishi',
-  }
+    koishi: 'koishi',
+    'koishi-utils-schemagen': 'koishi-utils-schemagen',
+  },
 };