Environment variables can't be unset for agent_runtime deployments

### What happened?

Once an env var is set, it can't be removed. Only updated

### Steps to Reproduce

1. Set a var in .env
2. Deploy the agent
3. Remove the var in .env
4. Redeploy the agent

### What did you expect to happen?

The env var is not set anymore

### Client information

Client Information
CLI version: 1.1.0

### Command Output / Logs

_No response_

### Anything else we need to know?

The culprit is that the cli always includes the variables from previous deployments.