Switch back to upstream terser gem

We temporarily used a fork to get around a UTF-8 encoding issue with
LICENSE (https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/5716),
which was fixed in https://github.com/ahorek/terser-ruby/pull/6. We
switch back to the upstream library now that this has been resolved.

Full diff:
https://github.com/ahorek/terser-ruby/compare/1.0.1..1.0.2

Gemfile

@@ -290,7 +290,7 @@ gem 'gitlab_chronic_duration', '~> 0.10.6.2'
 gem 'rack-proxy', '~> 0.6.0'
 
 gem 'sassc-rails', '~> 2.1.0'
-gem 'gitlab-terser', '1.0.1.1'
+gem 'terser', '1.0.2'
 
 gem 'addressable', '~> 2.7'
 gem 'font-awesome-rails', '~> 4.7'

Gemfile.lock

@@ -452,8 +452,6 @@ GEM
       rubocop-performance (~> 1.5.2)
       rubocop-rails (~> 2.5)
       rubocop-rspec (~> 1.36)
-    gitlab-terser (1.0.1.1)
-      execjs (>= 0.3.0, < 3)
     gitlab_chronic_duration (0.10.6.2)
       numerizer (~> 0.2)
     gitlab_omniauth-ldap (2.1.1)
@@ -1132,6 +1130,8 @@ GEM
     temple (0.8.2)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
+    terser (1.0.2)
+      execjs (>= 0.3.0, < 3)
     test-prof (0.12.0)
     text (1.3.1)
     thin (1.7.2)
@@ -1333,7 +1333,6 @@ DEPENDENCIES
   gitlab-puma_worker_killer (~> 0.1.1.gitlab.1)
   gitlab-sidekiq-fetcher (= 0.5.2)
   gitlab-styles (~> 4.3.0)
-  gitlab-terser (= 1.0.1.1)
   gitlab_chronic_duration (~> 0.10.6.2)
   gitlab_omniauth-ldap (~> 2.1.1)
   gon (~> 6.2)
@@ -1483,6 +1482,7 @@ DEPENDENCIES
   stackprof (~> 0.2.15)
   state_machines-activerecord (~> 0.6.0)
   sys-filesystem (~> 1.1.6)
+  terser (= 1.0.2)
   test-prof (~> 0.12.0)
   thin (~> 1.7.0)
   timecop (~> 0.9.1)

config/initializers/sprockets.rb

-require 'terser'
-
 Sprockets.register_compressor 'application/javascript', :terser, Terser::Compressor