Paginate the merge requests API earlier to avoid eager loading every merge request
Paginate the merge requests API earlier to avoid eager loading every merge request

Fixes a performance regression introduced in !12732

stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,jirutka/gitlabhq,t-zuehlsdorff/gitlabhq,iiet/iiet-git,dplarson/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,dreampet/gitlab,jirutka/gitlabhq,dplarson/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,iiet/iiet-git,mmkassem/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,axilleas/gitlabhq,jirutka/gitlabhq,dreampet/gitlab,dplarson/gitlabhq,t-zuehlsdorff/gitlabhq,jirutka/gitlabhq,dplarson/gitlabhq,axilleas/gitlabhq,axilleas/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,dreampet/gitlab