Remove Sentry/GlitchTip integration

- main.js: drop @sentry/browser + @sentry/vue init.
- webpack.config.prod.js: drop sentryWebpackPlugin (and its dotenv/env
  plumbing that only served Sentry release/source-map upload).
- package.json: remove @sentry/browser, @sentry/vue, @sentry/webpack-plugin.

Note: run 'npm install' to update package-lock before the next build.

package.json

@@ -19,8 +19,6 @@
   "author": "Bachir Soussi Chiadmi",
   "license": "MIT",
   "dependencies": {
-    "@sentry/browser": "^9.8.0",
-    "@sentry/vue": "^9.8.0",
     "axios": "^0.21.0",
     "check-password-strength": "^1.0.15",
     "pretty-bytes": "^5.5.0",
@@ -40,7 +38,6 @@
     "@babel/plugin-syntax-dynamic-import": "^7.8.3",
     "@babel/preset-env": "^7.12.7",
     "@kazupon/vue-i18n-loader": "^0.5.0",
-    "@sentry/webpack-plugin": "^3.2.2",
     "@vue/test-utils": "^1.1.1",
     "babel-core": "^7.0.0-bridge.0",
     "babel-eslint": "^10.1.0",