Bump labkit to 0.12.0

This includes the new related_class field.

Gemfile

@@ -301,7 +301,7 @@ gem 'sentry-raven', '~> 2.9'
 gem 'premailer-rails', '~> 1.10.3'
 
 # LabKit: Tracing and Correlation
-gem 'gitlab-labkit', '0.11.0'
+gem 'gitlab-labkit', '0.12.0'
 
 # I18n
 gem 'ruby_parser', '~> 3.8', require: false

Gemfile.lock

@@ -380,7 +380,7 @@ GEM
       rake (> 10, < 14)
       ruby-statistics (>= 2.1)
       thor (>= 0.19, < 2)
-    gitlab-labkit (0.11.0)
+    gitlab-labkit (0.12.0)
       actionpack (>= 5.0.0, < 6.1.0)
       activesupport (>= 5.0.0, < 6.1.0)
       grpc (~> 1.19)
@@ -1232,7 +1232,7 @@ DEPENDENCIES
   github-markup (~> 1.7.0)
   gitlab-chronic (~> 0.10.5)
   gitlab-derailed_benchmarks
-  gitlab-labkit (= 0.11.0)
+  gitlab-labkit (= 0.12.0)
   gitlab-license (~> 1.0)
   gitlab-mail_room (~> 0.0.3)
   gitlab-markup (~> 1.7.0)