Fix Link/SelfAssignment offense

.rubocop_todo.yml

@@ -107,11 +107,6 @@ Lint/MixedRegexpCaptureTypes:
 Lint/RedundantCopDisableDirective:
   Enabled: false
 
-# Offense count: 1
-Lint/SelfAssignment:
-  Exclude:
-    - 'spec/lib/gitlab/search_context/builder_spec.rb'
-
 # Offense count: 3
 Lint/StructNewOverride:
   Exclude:

spec/lib/gitlab/search_context/builder_spec.rb

@@ -43,7 +43,6 @@ RSpec.describe Gitlab::SearchContext::Builder, type: :controller do
   def be_search_context(project: nil, group: nil, snippets: [], ref: nil)
     group = project ? project.group : group
     snippets.compact!
-    ref = ref
 
     have_attributes(
       project: project,