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

For communities workflows, it is currently necessary to include tags under both sections (public and workflowhub) in `communities//metadata/workflow_tags` or the script does not create `communities//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
```