Reduce CI time taken by ci:build:compose

[make-github-pseudonymous-again]

Currently, ci:build:compose actively waits for ci:build:image to complete via ArcticLampyrid/action-wait-for-workflow. This counts as CI time even though we are only polling for ci:build:image to succeed. This is currently the only solution since those are two separate workflows.

Potential solution: merge ci:build:image and ci:build:compose into a single ci:build:container workflow with needs dependencies.

[make-github-pseudonymous-again]

This may be a duplicate of

• Use workflow_run trigger instead of ArcticLampyrid/action-wait-for-workflow #900