Revert "Update rouge to v3.10.0"

This reverts commit 3781ac1d.

Rouge v3.8.0+ has a bug in the JSON lexer:
https://github.com/rouge-ruby/rouge/issues/1330.

Let's revert until that is fixed.

Closes https://gitlab.com/gitlab-org/gitlab/issues/32045

Gemfile

@@ -148,7 +148,7 @@ gem 'wikicloth', '0.8.1'
 gem 'asciidoctor', '~> 2.0.10'
 gem 'asciidoctor-include-ext', '~> 0.3.1', require: false
 gem 'asciidoctor-plantuml', '0.0.9'
-gem 'rouge', '~> 3.10'
+gem 'rouge', '~> 3.7'
 gem 'truncato', '~> 0.7.11'
 gem 'bootstrap_form', '~> 4.2.0'
 gem 'nokogiri', '~> 1.10.4'

Gemfile.lock

@@ -834,7 +834,7 @@ GEM
     retriable (3.1.2)
     rinku (2.0.0)
     rotp (2.1.2)
-    rouge (3.10.0)
+    rouge (3.7.0)
     rqrcode (0.7.0)
       chunky_png
     rqrcode-rails3 (0.1.7)
@@ -1276,7 +1276,7 @@ DEPENDENCIES
   redis-rails (~> 5.0.2)
   request_store (~> 1.3)
   responders (~> 2.0)
-  rouge (~> 3.10)
+  rouge (~> 3.7)
   rqrcode-rails3 (~> 0.1.7)
   rspec-parameterized
   rspec-rails (~> 3.8.0)

changelogs/unreleased/update-rouge.yml

----
-title: Update rouge to v3.10.0
-merge_request: 32745
-author:
-type: other