Bump terser-webpack-plugin from 1.4.1 to 2.2.1 (#12233)

Bumps [terser-webpack-plugin](https://github.com/webpack-contrib/terser-webpack-plugin) from 1.4.1 to 2.2.1.
- [Release notes](https://github.com/webpack-contrib/terser-webpack-plugin/releases)
- [Changelog](https://github.com/webpack-contrib/terser-webpack-plugin/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/terser-webpack-plugin/compare/v1.4.1...v2.2.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -156,7 +156,7 @@
     "sass-loader": "^7.0.3",
     "stringz": "^2.0.0",
     "substring-trie": "^1.0.2",
-    "terser-webpack-plugin": "^1.4.1",
+    "terser-webpack-plugin": "^2.2.1",
     "tesseract.js": "^2.0.0-alpha.16",
     "throng": "^4.0.0",
     "tiny-queue": "^0.2.1",