Bump terser-webpack-plugin from 5.3.6 to 5.3.9

Bumps [terser-webpack-plugin](https://github.com/webpack-contrib/terser-webpack-plugin) from 5.3.6 to 5.3.9.
- [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](webpack-contrib/terser-webpack-plugin@v5.3.6...v5.3.9)

---
updated-dependencies:
- dependency-name: terser-webpack-plugin
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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