python-jsonschema: add dependency on importlib-metadata
With recently introduced updated jsonschema, it depends on importlib-metadata. https://github.com/Julian/jsonschema/blob/master/setup.cfg#L33 but it was not mention in Changelog.
Foris-controller crashes for now as it was not able to found:
ModuleNotFoundError: No module named 'importlib_metadata'
This just affects Turris OS 5.x as in Turris OS 4.x, there is an older version of jsonschema and in Turris OS 6.x, there's Python 3.8.