Experiment with new private runner machine types for gitlab-org/gitlab pipeline => 100%

Description

Provide @davis_townsend a cost benefit analysis and preference for newer GCP machine types e2, n2, c2, n2d for the entire gitlab-org/gitlab pipeline similar to gitlab-org/gitlab#213107.

Scoring

Cost and benefit analysis is delivered to Infrastructure by 2021-03-19, score will decrease by 10% for each week beyond that point