zink/ci: use the debian-built-testing for nvk

Fixes: 5b291c7ce652 ("ci: Move r300/nine/nvk builds out of critical path")
Signed-off-by: Martin Roukala (né Peres) <martin.roukala@mupuf.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33401>
1 file changed