Fix hashtags not being picked up when full-width hash sign is used (#36103)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

spec/models/tag_spec.rb

@@ -84,6 +84,10 @@ RSpec.describe Tag do
       expect(subject.match('this is #ａｅｓｔｈｅｔｉｃ').to_s).to eq '#ａｅｓｔｈｅｔｉｃ'
     end
 
+    it 'matches ＃ｆｏｏ' do
+      expect(subject.match('this is ＃ｆｏｏ').to_s).to eq '＃ｆｏｏ'
+    end
+
     it 'matches digits at the start' do
       expect(subject.match('hello #3d').to_s).to eq '#3d'
     end