ci: don't remove wget from the packages of debian/x86_test-vk

ci: don't remove wget from the packages of debian/x86_test-vk

The 'wget' package was in the list of ephemeral packages used only during the
build. 'Wget' installation comes from the build for the 'x86_build-base', and
the inclusion on this list only affects its purge. Jobs that use this image,
like 'venus-lavapipe' in 'virglrenderer', cannot use it as other GL jobs can.
So, please don't consider this package ephemeral when it comes from the upper
layer builder.

This 'wget' package is a known dependency on a job that uses this image. So,
even if this package is installed in the base image, it is good to have it
explicitly mentioned in the packages to install.

Signed-off-by: Sergi Blanch Torne <sergi.blanch.torne@collabora.com>
Reviewed-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19784>