test/py/requirements.txt: Bump zipp to current release

A security issue exists with zipp before v3.19.1, and the current
release is now v3.19.2. While the change in versions numbers is large, a
manual inspection of the changelog shows that it's not as big as might
be implied.

Reported-by: GitHub dependabot
Signed-off-by: Tom Rini <trini@konsulko.com>