fix: fix require('@vue/babel-preset-app').version return undefined bug (#2393)

Author: lcoder

packages/@vue/cli-plugin-babel/index.js

@@ -36,7 +36,7 @@ module.exports = (api, options) => {
           .loader('cache-loader')
           .options(api.genCacheConfig('babel-loader', {
             '@babel/core': require('@babel/core/package.json').version,
-            '@vue/babel-preset-app': require('@vue/babel-preset-app').version,
+            '@vue/babel-preset-app': require('@vue/babel-preset-app/package.json').version,
             'babel-loader': require('babel-loader/package.json').version,
             modern: !!process.env.VUE_CLI_MODERN_BUILD,
             browserslist: api.service.pkg.browserslist