Disables autocomplete in filtered search

Sets `autocomplete=off` to issuable filtered serarch.

app/helpers/search_helper.rb

@@ -140,7 +140,8 @@ module SearchHelper
         placeholder: 'Search or filter results...',
         data: {
           'username-params' => @users.to_json(only: [:id, :username])
-        }
+        },
+        autocomplete: 'off'
       }
     if @project.present?

changelogs/unreleased/38877-disable-autocomplete-in-filtered-search.yml

+---
+title: Disables autocomplete in filtered searc
+merge_request: 15477
+author: Jacopo Beschi @jacopo-beschi
+type: added

spec/helpers/search_helper_spec.rb

@@ -102,6 +102,10 @@ describe SearchHelper do
       it 'includes project base-endpoint' do
         expect(search_filter_input_options('')[:data]['base-endpoint']).to eq(project_path(@project))
       end
+
+      it 'includes autocomplete=off flag' do
+        expect(search_filter_input_options('')[:autocomplete]).to eq('off')
+      end
     end
     context 'group' do