Bump uglifier from 4.1.20 to 4.2.0

Bumps [uglifier](https://github.com/lautis/uglifier) from 4.1.20 to 4.2.0.
- [Release notes](https://github.com/lautis/uglifier/releases)
- [Changelog](https://github.com/lautis/uglifier/blob/master/CHANGELOG.md)
- [Commits](https://github.com/lautis/uglifier/compare/v4.1.20...v4.2.0)

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

Gemfile.lock

@@ -219,7 +219,7 @@ GEM
     turbolinks-source (5.2.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    uglifier (4.1.20)
+    uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
     warden (1.2.8)
       rack (>= 2.0.6)
@@ -262,7 +262,7 @@ DEPENDENCIES
   sqlite3 (~> 1.4.1)
   turbolinks (~> 5.2.1)
   tzinfo-data
-  uglifier (~> 4.1.20)
+  uglifier (~> 4.2.0)
   web-console (~> 4.0.1)
   will_paginate (~> 3.1.8)
   will_paginate-bootstrap4 (~> 0.2.2)