gitlab-ci: Serve files for LAVA via separate service

Currently, we store the kernel and ramdisk for each LAVA job in the
artifacts of the job that built them. Because artifacts are stored in
GCE and LAVA labs aren't, this causes a lot of egress with is expensive.

To avoid this, have runners download most of the data via the (cached)
container images once, and for each job upload the kernel and ramdisk to
a server outside GCE.

Right now we only have Collabora's runner with a local web server, so
jobs that go to Baylibre's lab have been disabled.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4295>
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index dcbbb58..d152387 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -162,7 +162,7 @@
     - .fdo.container-ifnot-exists@debian@arm64v8
     - .container
   variables:
-    FDO_DISTRIBUTION_TAG: &arm_build "2020-03-17-db820c"
+    FDO_DISTRIBUTION_TAG: &arm_build "2020-03-24"
 
 .use-arm_build:
   variables: