Remove pipeline editor button from blob view

Now that we have the split button enabled by default,
we can remove the side pipeline editor button
to avoid having 2 options that lead to the
same page.

Changelog: changed

app/views/projects/blob/_header.html.haml

@@ -6,8 +6,6 @@
   .file-actions.gl-display-flex.gl-align-items-center.gl-flex-wrap.gl-md-justify-content-end<
     = render 'projects/blob/viewer_switcher', blob: blob unless blame
     = render 'shared/web_ide_button', blob: blob
-    - if show_pipeline_editor_button?(@project, @path)
-      = link_to "Pipeline Editor", project_ci_pipeline_editor_path(@project, branch_name: @ref), class: "btn gl-button btn-confirm-secondary gl-ml-3"
     .btn-group{ role: "group", class: ("gl-ml-3" if current_user) }>
       = render_if_exists 'projects/blob/header_file_locks_link'
       - if current_user