If we don't call #to_a, we're relying on the members already being loaded from
elsewhere. Otherwise we'll do a separate query for each user:

    [1] pry(main)> Project.first.team.members.include?(User.first)
      Project Load (0.7ms)  SELECT  "projects".* FROM "projects"  ORDER BY "projects"."id" ASC LIMIT 1
      ↳ (pry):3
      User Load (1.8ms)  SELECT  "users".* FROM "users"  ORDER BY "users"."id" ASC LIMIT 1
      ↳ (pry):3
      User Exists (0.6ms)  SELECT  1 AS one FROM "users" INNER JOIN "project_authorizations" ON "users"."id" = "project_authorizations"."user_id" WHERE "project_authorizations"."project_id" = $1 AND "users"."id" = $2 LIMIT 1  [["project_id", 1], ["id", 1]]
      ↳ (pry):3
    => true
    [2] pry(main)> Project.first.team.members.to_a.include?(User.first)
      Project Load (12.8ms)  SELECT  "projects".* FROM "projects"  ORDER BY "projects"."id" ASC LIMIT 1
      ↳ (pry):1
      User Load (9.6ms)  SELECT "users".* FROM "users" INNER JOIN "project_authorizations" ON "users"."id" = "project_authorizations"."user_id" WHERE "project_authorizations"."project_id" = $1  [["project_id", 1]]
      ↳ (pry):1
      User Load (0.6ms)  SELECT  "users".* FROM "users"  ORDER BY "users"."id" ASC LIMIT 1
      ↳ (pry):1
    => true