Update project hooks limits to 100 for all plans
What does this MR do?
In !20730 (merged) we introduced project hook limits of 10/20/30/100 for Free/Bronze/Silver/Gold tiers. We like to increase the limits to 100 for all plans.
I'm not sure if we need to test this migration –even though we are migrating data– we are using the create_or_update_plan_limit helper.
https://docs.gitlab.com/ee/development/testing_guide/testing_migrations_guide.html
I'm happy to add a spec for the data migration that is basically a copy from this one https://gitlab.com/gitlab-org/gitlab/blob/v12.6.2-ee/spec/migrations/insert_project_hooks_plan_limits_spec.rb