Project: delete the `.jobsets` jobset if project is no longer declarative

Dependencies

• [2] 6WRGCITD Enable declarative projects.
• [*] FPK5LF53 * Put the project-related actions in a separate controller. Put the

Change contents

• edit in src/lib/Hydra/Controller/Project.pm at line 172
  [2.703]

  [2.703]
  + } else {

  + $project->jobsets->search({ name => ".jobsets" })->delete;