Bump webpacker from 4.0.7 to 4.2.0 (mastodon#12416)

* Bump webpacker from 4.0.7 to 4.2.0

Bumps [webpacker](https://github.com/rails/webpacker) from 4.0.7 to 4.2.0.
- [Release notes](https://github.com/rails/webpacker/releases)
- [Changelog](https://github.com/rails/webpacker/blob/master/CHANGELOG.md)
- [Commits](rails/webpacker@v4.0.7...v4.2.0)

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

* Use NODE_ENV=tests instead of test, to work around async modules not having a chunk

.env.test

@@ -1,5 +1,5 @@
 # Node.js
-NODE_ENV=test
+NODE_ENV=tests
 # Federation
 LOCAL_DOMAIN=cb6e6126.ngrok.io
 LOCAL_HTTPS=true

Gemfile

@@ -93,7 +93,7 @@ gem 'tty-command', '~> 0.9', require: false
 gem 'tty-prompt', '~> 0.19', require: false
 gem 'twitter-text', '~> 1.14'
 gem 'tzinfo-data', '~> 1.2019'
-gem 'webpacker', '~> 4.0'
+gem 'webpacker', '~> 4.2'
 gem 'webpush'
 
 gem 'json-ld', git: 'https://github.com/ruby-rdf/json-ld.git', ref: 'e742697a0906e74e8bb777ef98137bc3955d981d'

Gemfile.lock

@@ -660,7 +660,7 @@ GEM
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    webpacker (4.0.7)
+    webpacker (4.2.0)
       activesupport (>= 4.2)
       rack-proxy (>= 0.6.1)
       railties (>= 4.2)
@@ -800,7 +800,7 @@ DEPENDENCIES
   twitter-text (~> 1.14)
   tzinfo-data (~> 1.2019)
   webmock (~> 3.7)
-  webpacker (~> 4.0)
+  webpacker (~> 4.2)
   webpush
 
 RUBY VERSION