Bump uglify-js from 3.13.8 to 3.13.9

Bumps [uglify-js](https://github.com/mishoo/UglifyJS) from 3.13.8 to 3.13.9.
- [Release notes](https://github.com/mishoo/UglifyJS/releases)
- [Commits](mishoo/UglifyJS@v3.13.8...v3.13.9)

---
updated-dependencies:
- dependency-name: uglify-js
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]