Update Jenkinsfile build agent to improve build stability

• Update Jenkinsfile build agent to improve build stability

Reuse of label for buildenv-agent means that the pod may be shared across different builds, which leads to errors in the build at times. To improve this, each project should have it's own unique label

requested review from @cguindon, @malowe, and @zacharysabourin

approved this merge request

merged

mentioned in commit 77b6ef4f