Necessity to include workflow tags for both public and workflowhub or codex crashes

[scorreard]

For communities workflows, it is currently necessary to include tags under both sections (public and workflowhub) in communities/<community-name>/metadata/workflow_tags or the script does not create communities/<community-name>/metadata/workflow_status.tsv

It would be great to modify the script for communities to be able to include tags in just one of the two sections if they want.

File example :

public:
- earth-system
- pangeo
- climate
workflowhub:
- earth-system
- pangeo
- climate