## About the changes
This PR adds the ability to push variants to multiple environments
overriding the existing variants.
Relates to [roadmap](https://github.com/orgs/Unleash/projects/10) item:
#2254
**Note:** This won't fail if there are variants in other environments, because the operation wouldn't be idempotent. It should have that property because setting variants to 1 or more environments once or twice should not make a difference
