ci: use multi env for docker build

[sebastiendan]

Description

This PR updates the docker build workflow so that docker images are tagged with environment. This is necessary as environment-specific env variable values are needed at build time.

PR Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added or updated tests that comprehensively prove my change is effective or that my feature works