Improve vulnerabilities database seed performance

The following discussion from !101546 (merged) should be addressed:

• @leetickett-gitlab started a discussion: (+2 comments)

  @bwill is it possible we accidentally changed this from seeding vulnerabilities for 5 projects to all projects?

  I'm just doing a fresh GCK install and noticed how long it took to run the 20_vulnerabilities seed

  Thanks 👍

Recreation Steps

git@gitlab-rails-web:~/gitlab$ bundle exec rails console
Vulnerabilities::Identifier.delete_all
Vulnerabilities::Scanner.delete_all
Ci::Pipeline.delete_all

git@gitlab-rails-web:~/gitlab$ bundle exec rake db:seed_fu FILTER=20_vuln

== Filtering seed files against regexp: /20_vuln/

== Seed from ee/db/fixtures/development/20_vulnerabilities.rb
2023-11-01T11:29:19+00:00

Seeding vulnerabilities for the 'toolbox/gitlab-smoke-tests' project
..............................
Done.

Seeding vulnerabilities for the 'gitlab-org/gitlab-test' project
..............................
Done.

Seeding vulnerabilities for the 'gitlab-org/gitlab-shell' project
..............................
Done.

Seeding vulnerabilities for the 'gnuwget/Wget2' project
..............................
Done.

Seeding vulnerabilities for the 'Commit451/lab-coat' project
..............................
Done.

Seeding vulnerabilities for the 'jashkenas/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'flightjs/Flight' project
..............................
Done.

Seeding vulnerabilities for the 'twitter/Typeahead.Js' project
..............................
Done.

Seeding vulnerabilities for the 'gaynell/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'claribel/gitlab-smoke-tests' project
..............................
Done.

Seeding vulnerabilities for the 'i-user-1-1698447830/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'i-user-0-1698447824/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'lisha.powlowski/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'windy.stehr/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'i-user-2-1698447827/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'i-user-2-1698447799/Underscore' project
..............................
Done.

Seeding vulnerabilities for the 'i-user-0-1698447799/gitlab-smoke-tests' project
..............................
Done.

Seeding vulnerabilities for the 'len/gitlab-smoke-tests' project
..............................
Done.
2023-11-01T13:30:07+00:00

OK

Implementation Guide

Modify lib/tasks/gitlab/seed.rake to limit the number of projects?

Perhaps something like projects = projects_from_args(args).shuffle(5)?

It would be great to dig further into ee/lib/quality/seeders/vulnerabilities.rb to see why this seed can be so slow.