Merge branch 'qa-shl-use-default-branch-in-wiki-push' into 'master'

Remove setting `@branch_name` in QA::Resource::Repository::WikiPush

See merge request gitlab-org/gitlab!65422

qa/qa/resource/repository/wiki_push.rb

@@ -16,7 +16,6 @@ module QA
           @file_name = 'Home.md'
           @file_content = 'This line was created using git push'
           @commit_message = 'Updating using git push'
-          @branch_name = 'master'
           @new_branch = false
         end