Offset pagination: Missing `LIMIT` clause

https://sentry.gitlab.net/gitlab/staginggitlabcom/issues/1099495/

PG::QueryCanceled: ERROR:  canceling statement due to statement timeout
...

ActiveRecord::QueryCanceled: PG::QueryCanceled: ERROR:  canceling statement due to statement timeout
: SELECT "projects".* FROM "projects" WHERE "projects"."visibility_level" = 20 AND "projects"."pending_delete" = FALSE ORDER BY "projects"."created_at" DESC, "projects"."id" DESC

This happens for requests to the Projects API, e.g. https://staging.gitlab.com/api/v4/projects.

The endpoint limits the result set but the limit isn't applied for all queries involved. When running this locally, we should see:

  Project Load (0.6ms)  SELECT  "projects".* FROM "projects" WHERE "projects"."visibility_level" = $1 AND "projects"."pending_delete" = $2 ORDER BY "projects"."created_at" DESC, "projects"."id" DESC LIMIT $3 OFFSET $4  [["visibility_level", 20], ["pending_delete", false], ["LIMIT", 20], ["OFFSET", 0]]
  ↳ app/services/projects/batch_count_service.rb:13

But instead, this became:

  Project Load (1.4ms)  SELECT "projects".* FROM "projects" WHERE "projects"."visibility_level" = $1 AND "projects"."pending_delete" = $2 ORDER BY "projects"."created_at" DESC, "projects"."id" DESC  [["visibility_level", 20], ["pending_delete", false]]
  ↳ app/services/projects/batch_count_service.rb:13

Note the LIMIT is still applied correctly to the query actually loading projects:

  Project Load (0.6ms)  SELECT  "projects".* FROM "projects" WHERE "projects"."visibility_level" = $1 AND "projects"."pending_delete" = $2 ORDER BY "projects"."created_at" DESC, "projects"."id" DESC LIMIT $3 OFFSET $4  [["visibility_level", 20], ["pending_delete", false], ["LIMIT", 20], ["OFFSET", 0]]
  ↳ lib/api/projects.rb:98