Upgrade C4 PlantUML definition files to 2.7.0

[rlespinasse]

Resolves #1604

[rlespinasse]

Build failed on kroki-wireviz build which seem not related to the PR scope. Any idea on why?

 > [kroki-wireviz 6/7] RUN apk --update --no-cache add --virtual build-dependencies build-base python3-dev   && pip install --no-cache-dir -r requirements.txt   && apk del build-dependencies:
37.77 error: subprocess-exited-with-error
37.77 
37.77 × Getting requirements to build wheel did not run successfully.
37.77 │ exit code: 1
37.77 ╰─> See above for output.

[ggrossetie]

Thank you 🙌