Add concurrency limit for mirroring and update gitlab ci to work with…

[nick-vanpraet]

… new API changes for DXP

Summary

Trying to tackle the mirroring bug (it happens when another mirroring task is running at the same time)
Updating pipeline to auto-build QA envs, API changed on DXP's side

Metadata

Question	Answer
Did you use a meaningful pull request title?	yes/no
Did you apply meaningful labels to the pull request?	yes/no
Did you perform a self review first?	yes/no
Documentation reflects changes?	yes/no
CHANGELOG reflects changes?	yes/no
Unit/Functional tests reflect changes?	yes/no
Did you perform browser testing?	yes/no
Risk level	Low, Medium, High
Relevant links	JIRA issue, bug reports, security alerts, etc.