test/tool-option-parsing: switch from pytest to unittest For me, installing pytest for libxkbcommon is a bit problematic, so I end up skipping it which is not great. Switch to unittest which is built in to Python. It's not as nice as pytest but good enough in this case. Note: I was too lazy to switch the plain asserts to unittest assertions... Signed-off-by: Ran Benita <ran@unusedvar.com>