Fix test failure of jh/spec/lib/jh/gitlab/project_template_spec.rb

Fix test failure of jh/spec/lib/jh/gitlab/project_template_spec.rb, upstream update the template name of sse_middleman to middleman, so I update the test.

Upstream commit https://gitlab.com/gitlab-org/gitlab/-/commit/1eeda79e95a4a60e891818dfb089af9360fb495b

Upstream MR https://gitlab.com/gitlab-org/gitlab/-/merge_requests/82231