Merge branch 'dm-remove-double-project-nav-bar' into 'master'

Don't show double nav bar on project page when activity is the default project view

Closes #29096

See merge request !9798

app/views/projects/_activity.html.haml

 - @no_container = true
-= render "projects/head"
 
 %div{ class: container_class }
   .nav-block.activity-filter-block

app/views/projects/activity.html.haml

 - page_title "Activity"
+= render "projects/head"
 
 = render 'projects/last_push'