style: delete ga plugin package

Author: reco_luan

package.json

@@ -32,7 +32,6 @@
     "@vuepress-reco/vuepress-plugin-loading-page": "^1.0.2",
     "@vuepress-reco/vuepress-plugin-pagation": "^1.0.4",
     "@vuepress-reco/vuepress-plugin-screenfull": "^1.0.1",
-    "@vuepress-reco/vuepress-plugin-ga": "^1.0.2",
     "@vuepress-reco/vuepress-plugin-comments": "^1.0.8",
     "@vuepress/plugin-medium-zoom": "1.2.0",
     "@vuepress/plugin-blog": "1.3.0",