Merge branch 'sh-remove-banzai-instrumentation' into 'master'

Remove method instrumentation for Banzai filters and reference parsers

See merge request gitlab-org/gitlab-ce!20770

changelogs/unreleased/sh-remove-banzai-instrumentation.yml

+---
+title: Remove method instrumentation for Banzai filters and reference parsers
+merge_request: 20770
+author:
+type: performance

config/initializers/8_metrics.rb

@@ -58,20 +58,6 @@ def instrument_classes(instrumentation)
     instrumentation.instrument_instance_methods(const)
   end
 
-  # Instruments all Banzai filters and reference parsers
-  {
-    Filter: Rails.root.join('lib', 'banzai', 'filter', '*.rb'),
-    ReferenceParser: Rails.root.join('lib', 'banzai', 'reference_parser', '*.rb')
-  }.each do |const_name, path|
-    Dir[path].each do |file|
-      klass = File.basename(file, File.extname(file)).camelize
-      const = Banzai.const_get(const_name).const_get(klass)
-
-      instrumentation.instrument_methods(const)
-      instrumentation.instrument_instance_methods(const)
-    end
-  end
-
   instrumentation.instrument_methods(Banzai::Renderer)
   instrumentation.instrument_methods(Banzai::Querying)