Bump uglifier from 4.2.0 to 4.2.1

Bumps [uglifier](https://github.com/lautis/uglifier) from 4.2.0 to 4.2.1.
- [Changelog](https://github.com/lautis/uglifier/blob/master/CHANGELOG.md)
- [Commits](lautis/uglifier@v4.2.0...v4.2.1)

---
updated-dependencies:
- dependency-name: uglifier
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -646,7 +646,7 @@ GEM
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     uber (0.1.0)
-    uglifier (4.2.0)
+    uglifier (4.2.1)
       execjs (>= 0.3.0, < 3)
     unf (0.2.0)
     unicode-display_width (2.5.0)