Fix flaky open_fork_in_web_ide_spec.rb

Use different user and delete artifacts after the test

qa/qa/specs/features/browser_ui/3_create/web_ide/open_fork_in_web_ide_spec.rb

@@ -11,7 +11,7 @@ module QA
       end
 
       context 'when a user does not have permissions to commit to the project' do
-        let(:user) { Resource::User.fabricate_or_use(Runtime::Env.gitlab_qa_username_1, Runtime::Env.gitlab_qa_password_1) }
+        let(:user) { Resource::User.fabricate_or_use(Runtime::Env.gitlab_qa_username_6, Runtime::Env.gitlab_qa_password_6) }
 
         context 'when no fork is present' do
           it 'suggests to create a fork when a user clicks Web IDE in the main project', testcase: 'https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/347823' do
@@ -45,6 +45,10 @@ module QA
 
             submit_merge_request_upstream
           end
+
+          after do
+            fork_project.project.remove_via_api!
+          end
         end
 
         def submit_merge_request_upstream