migrate to plugin support

[alec-c4]

Hi!
I have the following config in my .rubocop config

require:
  - standard

plugins:
  - rubocop-rails
  - rubocop-rspec
  - rubocop-performance
  - rubocop-thread_safety
  - rubocop-factory_bot
  - rubocop-capybara

but to use standard as a plugin, I'd like to ask you to add plugin support https://docs.rubocop.org/rubocop/plugin_migration_guide.html

[jeffbax]

I attempted to update my .rubocop.yml config as according to the warnings, but ran into flaky behavior on CI that I think is ultimately due to the version of Rubocop that is out for the latest Standard -- rubocop/rubocop#13950

So hopefully the next update will resolve this?