package/python-jinja2: fix runtime python modules dependencies

- add python unicodedata runtime dependency, fixes:
  File "usr/lib/python3.8/site-packages/jinja2/lexer.py", line 46, in <module>
  ModuleNotFoundError: No module named 'unicodedata'

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>