[CI] Use "environments" to better track and clean up releases
Adds environments to CI, ensuring that:
- Environments are automatically cleaned up upon merge or after 4 days
- Concurrent pipelines on the same branch cannot deploy to the same environment at the same time (using resource groups)
- Cleanup jobs are only run when required
Referenced the Charts CI configuration to maintain some parity between the projects.
Closes #230 (closed)
Edited by Mitchell Nielsen