Project#manual_sync: cease saving the project record bc we're just kicking off async workers.

[tiegz]

The Project#manual_sync method was added in https://github.com/librariesio/libraries.io/commit/e95cee4857425e139b6946378f48efe6fcc692ab and kicks off async jobs to update a project, so nothing in that method call actually should update the Project. But there's a forced_save in that method that just saves the record with a new :updated_at.

From my archaeological dig, I believe that forced_save was just to ensure that Elasticsearch record for the Project was updated, but manual_sync shouldn't be updating anything in the Project since it just kicks off async jobs.

The unintended side-effects of this forced_save call is the callback chain that happens with it:

  # kicks off an expensive job that queries the `dependencies` table
  after_commit :set_dependents_count_async, on: %i[create update]

  # kicks off a job to update the source rank
  after_commit :update_source_rank_async, on: %i[create update]

  # kicks off a ProjectUpdatedWorker for every webhook that wants project updates (!!!)
  after_commit :send_project_updated, on: %i[create update]

  # does a bunch of column-setting
  before_save  :update_details

the above is a waste of effort, considering that it will happen again after the async PackageManagerDownloadWorker has completed. The part that I really want to eliminate is the ProjectUpdatedWorker jobs.