[CI] Simplify Docker containers (#21175)
Get rid of the `base` container and the current `latest` container and
move the current `intel_drivers` `alldeps` container to `latest`.
Nobody was using the `base` container directly, and it's only used in
one place transitively, the UR liboffload workflow, through the
`intel_drivers`:`latest` tag.
Lets just simply everything.
This PR isn't updating any workflows because we need the containers in
this PR to be published first.
---------
Signed-off-by: Nick Sarnie <nick.sarnie@intel.com>
