debian-bookworm-build: add deps for osmo-dev test
Prepare to run new tests for gen_makefile.py in osmo-dev in CI. This
requires pytest and open5gs dependencies to pass "meson setup".
Related: osmo-dev I8bb2af7ffb902fd690e83e36739c2b4415b9ab80
Change-Id: I528565fe21b5989fff1d1b005e53136af5be429e
