Refactor the pipeline feature spec

What does this MR do?

In the spec/features/projects/pipelines/pipeline_spec.rb we visit the pipeline page in the before block. Causing in the ETag middleware without a status.

When visiting the page again after creating a status, the page would not be re-rendered. This makes sure we only access the page once per spec.

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/59747

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer