Work with QE / RE to get the 2.1.x branch ready for 2.1.0 release

Similar to SERVER-586, there is new information (QENG-2385, puppet-server email discussion) that came up this past sprint that leads us to believe the 2.1.x branch is not running all of the supported platform we're planning to ship for 2.1.0.

This ticket captures the work necessary to work with QE and RE in order to get the 2.1.x CI pipeline in shape ahead of the 2.1.0 release.

NOTE: As part of this ticket, we need to validate the LAYOUT axis in the CI Job is correct relative to the planned 2.1.0 official release. We need to validate unsupported platforms are not included and all supported platforms are included.